Topic outline

  • General

  • Lecture 1. Introduction to Philosophy

    An Introduction to Philosophy

    The terms philosophus and philosophia were first employed by and roughly meant to Pythogoras as the pursuit of wisdom. The word philosophy (philosophia) is derived from two Greek words “ Philia” mean Love and “Sophia” mean wisdom. The term philosophy then in turn changed to signify wisdom and the love of it, which was seen as the highest kind of knowledge. There are various kinds of knowledge, for example knowledge we gain via our everyday experience of reality for example historical, literary, knowledge about the physical world, knowledge about art etc. There are also other forms of knowledge that we gain by making use of our intellect and capability to reason in order to classify, analyze, and interpret etc. the knowledge we gain from everyday experience. 

    We try to explain knowledge gained from our senses in order to understand and gain insight about their causes and reasons. Knowledge from our capability to reason in turn yield systemized truths which we call sciences. For example, knowledge about the physical world gained from our senses are in turn intellectually analyzed to yield certain truths about the physical world and thus rightly called the empirical physical sciences (e.g. physics and biology). 

    In this sense, philosophy is seen as a general science and its main aim is to answer deeper and more extensive questions and in order to do so, rational enquiry and reasoning needs to be employed to understand the more ultimate reasons and causes of things. Here it is important to distinguish between philosophy and theology. Theology tries to answer and reason about ultimate questions by making use of reason that is aided and enlightened by Divine revelation Philosophy properly understood is thus different from theology and different from the special sciences and properly defined as: the science of all things through their ultimate reasons and causes as discovered by the unaided capabilities of the human intellect and human reason.

                Wisdom is a matter not of knowledge but of understanding and insight. It is achieved by enquiring into the why of things rather than into their how or what. Such enquiries lead philosophy to ask questions that are more basic and fundamental than those asked by science: not "what is the cause of something?" but "Is it the case that everything has a cause?"  Unlike religion, philosophy wants to understand why things are the way they are and not simply to accept on faith that they must be so. Philosophy may in part be defined as an attempt, by way of reason alone; to gain an understanding of our nature and the nature of the world we live in.

    The philosophy also defines as “pursuit of knowledge” or “the search for truth”. Philosophy asks ultimate questions. Like, what is truth? How is Truth arrived at? What is knowledge? What is the essential nature of things? What is the good life? Philosophy seeks understanding. Clarity of understanding and defining terms. Help society and culture to be self-critical. Develop an ideology to guide people and society.

    Hence any branch of study was formerly called philosophy. As men were in the lowest stage of their intellec­tual development they could not differentiate the different depart­ments of the universe and consequently the different branches of knowledge.

    But with the advance of knowledge they came to distinguish different sciences from one another, and philosophy from sciences, and regarded philosophy as the knowledge of the eternal and essential nature of things. Thus at first, philosophy was not distinguished from special sciences; then it was altogether divorced from them.

    But now philosophy, in its restricted sense, means neither the study of any particular department of the universe, nor the knowledge of the eternal and essential nature of things and alone, but that highest branch of knowledge which aims at harmonizing and systematizing all truths and arriving at a rational conception of the reality as a whole, both in its eternal and temporal aspects. Philosophy is the criticism of life and experience.

    The prime concern of philosophy is life. Nothing in the universe is beyond life and nothing in

    Life is beyond philosophy. Moreover, philosophy is the criticism and interpretation of life. It

    enquires into the nature, meaning, purpose, origin and destiny of human life.

    The chief instrument of philosophy is logic. Being logical, it does not want to believe

     anything without logic. Its method is rational speculation – logical analysis and synthesis.

    Because of its dealing with scientific method, everything of philosophy is methodical based

    on science.

    In fine, we must say that philosophy is a vast field where all branches of knowledge get place to stay as well as to be discussed. Indeed different sciences deal with different departments of the world and give us a sectional view of the world. Philosophy harmonizes the highest conclusions of the different sciences, co-ordinates them one another, and gives a rational conception of the whole world. So philosophy is very important for us as a subject.

     

    Various Definitions of Philosophy

    Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational argument.

    Heraclitus

    Philosophy is a sacred disease.

    Plato

    “Philosophy aims at the knowledge of the eternal, of the essential nature of things”

    Aristotle

    “Philosophy is the science which investigates the nature of Being as it is in itself, and the attributes which belong to it in virtue of its own nature” 

    Immanuel Kant

    “Philosophy is the science and criticism of cognition

    J.G. Fichte

                 “Philosophy is the science of knowledge”

    Gomte

     “Philosophy is the science of sciences”

    Hegel

    To comprehend what is is the task of philosophy, for what is is reason.

    Karl Marx

    The philosophers have only interpreted the world, in various ways; the point, however, is to change it.

    William James

    "Philosophy is the unusually stubborn attempt to think clearly."

     Paulsen

    “Philosophy is the sum total of all scientific knowledge”.

     Wundt

    “Philosophy is the unification of all knowledge obtained by the special sciences in a consistent whole”

    Herbert Spencer

    “Philosophy is completely unified knowledge—the gener­alizations of philosophy comprehending and consolidating the widest generalizations of science”

    Nietzsche

    Philosophy is this tyrannical drive itself, the most spiritual will to power.

     G. E. Moore

    "It is what these are about."

    Wittgenstein

    All philosophy is a 'critique of language'


    • Lecture 2. Scope of Philosophy

      The Scope of Philosophy

              The term “scope” simply refers to all those things that fall within the umbrella of a concept. Hence, the scope of philosophy entails those elements in reality that is encapsulated in the day to day activities of the philosophical enterprise. Simply put, the scope of philosophy discusses what philosophy talks about and what philosophy does not talk about; and this is highlighted below;

      Philosophy talks about universals and general realities. It sees things from the widest perspective. It perceives things as a whole. It considers the entirety of being as a vast interconnected system. This is why philosophy is regarded as a universal discipline. For example; if philosophy were to talk about man, it would do so in connection with those elements that are globally and objectively present in all men.

      In contrast to the above, philosophy, due to its nature does not talk about particulars or individual entities. It is not concerned with specifics. It would never consider reality in isolation from the whole. For example; considering the problem of democracy, philosophy is not concerned with the democracy of a particular country alone (like Nigeria) but the concept of democracy on a global scale.

       

      Scope / Branches of Philosophy

      Western philosophy can be divided into six branches that have assumed various importance over time. Traditionally metaphysics sets the questions for philosophy. Epistemology asks how do we know? Ethics and politics have to do with action and quality of life. Aesthetics or value theory has to do with beauty, balance, and harmony. Logic has to do with the relations of things. Epistemology sometimes replaces metaphysics these days, because it has fewer religious overtones. Among Eastern European and continental philosophers, philosophy tends to be the study of politics. Logic is critical for analytic philosophers, who are deeply suspicious of ethics, politics, and metaphysics.

      Understanding philosophy in the 6th century B.C. involves taking into account different priorities than those of the 19th century a.d. However, these divisions remain helpful for identifying what's at stake. Metaphysics, which studies the nature of existence, is closely related to Epistemology, the study of knowledge and how we know what we do about the world around us. Ethics, the study of how individuals should act, depends on Epistemology, because we need knowledge to make good choices. Politics studies human interaction. Aesthetics studies the value of things. Logic is about the symbolic representation of language and thought processes. Once the domain of Aristotle, the foundation of the exact sciences must now take into account relativity, uncertainty and incompleteness. 5/17

      Epistemology

      The theory of knowledge, from the Greek words episteme (knowledge) and logos (word/speech/study), is the branch of philosophy that deals with the nature, origin, scope and (possibility/study) of knowledge. Dealing with nature is one of the branches of philosophy. But before anything is done, the meaning of philosophy should be understood. A philosopher of religion must be objective. Anyone who is ready to study philosophy should be able to attack and defend. In other definition logic is the study of reasoning. It can also be described as the study of strength of the evident links between the premises and the conclusion. Logic is further divided into deductive reasoning and inductive reasoning. Deductive reasoning proceeds from a general statement to a particular statement. It is mostly a valid argument given that is tautological in nature. This means that the conclusion bares no new knowledge that it (conclusion) is missing in the premises. Inductive argument: This reasoning perceives from a particular statement to a general statement. This reasoning is mostly utilized in the scientific researches

      Metaphysics

      Metaphysics however (derived from the Greek words " meta & physika ") - meaning 'after physics'. It was the way students referred to a specific book in the works of Aristotle, and it was a book on First Philosophy. (The assumption that the word means "beyond physics" is misleading) Metaphysics is the branch of philosophy concerned with the study of "first principles" and "being" (ontology). In other words, Metaphysics is the study of the most general aspects of reality, pertaining to subjects such as substance, identity, the nature of the mind, and free will. It is a study of nature, the nature of reality, and the nature of the world in which humans live.

      Metaphysics: it deals with the abstract idea and they are what you cannot see touch but they exist…… its an unseen reality.

      Logic

      Logic (from Classical Greek λόγος (logos), originally meaning the word, or what is spoken, but coming to mean thought or reason is most often said to be the study of arguments. Logic is the study of correct reasoning. However the subject is grounded, the task of the logician is the same: to advance an account of valid and fallacious inference to allow one to distinguish.

      Ethics

      Ethics is a general term for what is often described as the "science (study) of morality". In philosophy, ethical behavior is that which is "good" or "right". The Western tradition of ethics is sometimes called moral philosophy.Its the study of right and wrong in human endeavors

      Aesthetics

      Aesthetics is a branch of philosophy that explores the creation and appreciation of beauty through critical analysis and reflection. According to Ogundola Blessing Ekundayo(2020), Aesthetics as a a branch of philosophy connotes the concept of beauty and also the ethics of education. Beauty is manifest in nature, object, thing and phenomenon but expressed in art.

      Other Branches

      Philosophy of Education: Fairly self-explanatory. A minor branch, mainly concerned with what is the correct way to educate a person. Classic works include Plato's Republic, Locke's Thoughts Concerning Education, and Rousseau's Emile.

      Philosophy of History: Fairly minor branch (not as minor as education), although highly important to Hegel and those who followed him, most notably Marx. It is the philosophical study of history, particularly concerned with the question whether history (i.e. the universe and/or humankind) is progressing towards a specific end? Hegel argued that it was, as did Marx. Classic works include Vico's New Science, and Hegel and Marx's works.

      Philosophy of Language: Ancient branch of philosophy which gained prominence in the last century under Wittgenstein. Basically concerned with how our languages affect our thought. Wittgenstein famously asserted that the limits of our languages mark the limits of our thought. Classic works include Plato's Cratylus, Locke's Essay, and Wittgenstein's Tractatus Logico-Philosophicus.

      Philosophy of Law: Also called Jurisprudence. Study of law attempting to discern what the best laws might be, how laws came into being in the first place, attempting to delimit human laws from natural laws, whether we should always obey the law, and so on. Law isn't often directly dealt with by philosophers, but much of political philosophy obviously has a bearing on it.

      Philosophy of Mathematics: Concerned with issues such as, the nature of the axioms and symbols (numbers, triangle, operands) of mathematics that we use to understand the world, do perfect mathematical forms exist in the real world, and so on. Principia Mathematica is almost certainly the most important work in this field.

      Philosophy of Mind: Study of the mind, attempting to ascertain exactly what the mind is, how it interacts with our body, do other minds exist, how does it work, and so on. Probably the most popular branch of philosophy right now, it has expanded to include issues of AI. Classic works include Plato's Republic and Wittgenstein's Philosophical Investigations, although every major philosopher has had some opinion at least on what the mind is and how it works.

      Philosophy of Politics: Closely related to ethics, this is a study of government and nations, particularly how they came about, what makes good governments, what obligations citizens have towards their government, and so on. Classic works include Plato's Republic, Hobbes' Leviathan, Locke's Two Treatises, and J.S. Mill's On Liberty.

      Philosophy of Religion: Theology is concerned with the study of God, recommending the best religious practises, how our religion should shape our life, and so on. Philosophy of religion is concerned with much the same issues, but where Theology uses religious works, like the Bible, as its authority, philosophy likes to use reason as the ultimate authority.

      Philosophy of Science: It is the Study of science concerned with whether scientific knowledge can be said to be certain, how we obtain it, can science really explain everything, does causation really exist, can every event in the universe be described in terms of physics and so on. Also popular in recent times, classic works include Hume's Treatise on Human Nature, Kripke's Naming and Necessity, Kuhn's Structure of Scientific Revolutions.


      • Basic Questions Of Greek Philosophy

        THE PHYSIS PROBLEM

        The Milesian philosophers—Thales, Anaximander, and Anaximines—set up a pattern of questions that all later Presocratic philosophers then tried to answer. The first and most fundamental of these was the question: what is the most basic or underlying substance of the world?

        This question, the question of physis, can actually be broken down into two separate questions. The search for a physis is, first of all, a search for some substance out of which everything else in the world arose. In this sense, we might say that according to modern science the physis of the world is subatomic particles. Everything in the world, as far as we know, is built up out of these particles.

        The search for a physis is also the search for a unifier within nature—either for some substance that is the most basic constituent of the world and of which everything else is somehow a variation, or else for some pattern through which all things in the world form a unity. For the Presocratics the physis was either one or the other of these—i.e. either some basic constituent or some lawlike pattern. To try once again to apply the physis problem to modern science, today we would probably say that the physis, in this second sense, is both a basic constituent (again the subatomic particles) and a lawlike pattern (the laws of quantum mechanics that govern the behavior of these subatomic particles).

        Thales, as the first philosopher, was the first to treat the physis problem. According to Thales the physis of the world is water. But water was only Thales' physis in the first sense—as the substance out of which everything else arose. From the sparse fragments that remain to us of Thales' thought, it does not appear as if he considered the second part of the physis problem, the problem of a unifier within nature. Anaximander, a student of Thales, proposed a different physis. His physis was an infinite, indefinite substance, that he referred to as the "apeiron". The apeiron, like all the later candidates for physis, was meant to be a physis in both the above senses.

        Anaximander's student Anaximines theorized that the physis was something he called "aer", an infinite substance, but not an indefinite one. Aer, is like a thick, misty air. For Xenophanes there were two physis, earth and water. Heraclitus was the first to propose that the unifier in nature was not some basic material constituent, but rather some structure, law, or plan within nature. He called this structure the "logos" and believed that it controlled the entire natural world.

        For Parmenides there was only a single real thing in the world, the unified, unchanging, unmoving reality, and so there really was no need for a question of physis. The Pluralists, however, who tried to revive natural philosophy in Parmenides' wake, returned to the physis problem. According to Empedocles the physis were the four elements, for Anaxagoras the physis was an infinite number of homeomeric substances (i.e. substances without differentiated parts), and for the Atomists, the physis were tiny, indivisible, imperceptible atoms.

        THE PLURALITY PROBLEM

        The second question that the Milesians posed, and that all later Presocratics tried to answer, is the plurality problem. The plurality problem asks how a single physis could give rise to the plurality of objects we observe in the world. Obviously, the question is based on the assumption made in the physis problem: that we can get the present cosmological structure in its full qualitative variety from a single fundamental substance (or, for Heraclitus, pattern or law).

        Thales, as far as we know (again there is the problem of scarce fragments) did not treat the plurality problem, but starting from Anaxagoras the plurality problem became as central a concern to Presocratics as the question of physis. Anaxagoras was not only the first to treat this problem, but he also lay the framework through which many later philosophers would view it. According to Anaxagoras, the key to solving the plurality problem lay in the assumption of a basic polarity of opposites within the original physis (for him, the indefinite apeiron). These opposites (in particular, hot and cold) somehow separate off from the physis, through the eternal motion that the physis undergoes. The hot takes the form of fire, which in turn can coalesce into the sun and other heavenly bodies. The cold becomes dark mist (watery substance), which can then transform into air and earth once it is dried by the heat of fire.

        Anaximines also solves the plurality problem by appealing to an eternal motion within his physis, but he makes a definite advance over his teacher by positing a detailed mechanism though which the elements become differentiated. His physis (aer) is transformed into everything else in the world through the processes of condensation and rarefaction. When aer rarifies it becomes fire, when it condenses it becomes wind, then water, then clouds, then earth, and then, finally, stone.

        It is unclear how Xenophanes treated this problem (if he did at all), because we have very few fragments pertaining to his natural philosophy.

        Heraclitus, like Anaxagoras, appeals to the idea of opposites inherent within nature in order to solve the plurality problem. According to Heraclitus's solution, though, there is really no such problem to begin with: the world begins as a plurality, a constant tension between opposites, which are also somehow unified through the logos.

        For Parmenides there is no plurality problem since there is no plurality. What exists is entirely unified. The pluralists, however, return to the problem of plurality. According to all of the pluralists, the plurality that we observe around us is explained as the result of mixtures between their physis: for Empedocles, everything is made out of certain proportions of the four elements, for Anaxagoras, everything is made out of certain ratios of homeomeric substances, and for the Atomists, all objects arise as the result of mixtures of atoms.

        THE MAINTENANCE PROBLEM

        The final problem in the Milesian legacy is the maintenance problem. The maintenance problem asks how the universe can retain its current orderly structure—what keeps the world acting in orderly patterns and maintaining its recognizable constancy?

        Again, Anaxagoras is the first philosopher we know of to have treated this problem. According to Anaxagoras the world maintains itself through a system much like human law courts. Though opposites are constantly struggling for dominance, nature pays out retributions and penalties to keep the opposites in line, maintaining their proper balance. There is a certain natural equilibrium or balance to the world, a kind of lawfulness within nature, and nature is always striving to maintain this equilibrium. Nature, in other words, is self- regulating. Anaximinies appears to agree with this view of an inherent equilibrium within nature, or, at least, we have no evidence that he disagreed. For Heraclitus, though, the picture is much more turbulent. Instead of occasional strife, which is constantly reigned in to a peaceful equilibrium, for Heraclitus the equilibrium within nature actually is a state of constant and universal strife between opposites. The logos, the pattern or law underlying all of nature, is responsible for maintaining this stormy equilibrium.

        For Parmenides, the problem of maintenance dissolves because there is no change at all in the world, but the pluralists revive the question. For Empedocles, it is the two corporeal motive forces, love and strife, that maintain order in the world, whereas for Anaxagoras that role is played by mind or nous, a rationality that controls all of nature. For the Atomists there was no need to posit any force that imposes order on the world, because they believed that order was the result of physical necessity.

        THE LIMITS OF HUMAN KNOWLEDGE

        The Milesians and the pluralists were primarily interested in natural philosophy—in the topics that we today would call physics, cosmology, and biology. Xenophanes, Heraclitus, and Parmenides, however, also had another preoccupation. They were interested in epistemology, or the study of knowledge.

        Xenophanes was the first to raise epistemological questions. He was a strong critic of the poets and of traditional belief. He urged his readers not to trust authority but to arrive at their beliefs through personal investigation. He believed in empiricism—that is, in deriving all beliefs through experience and observation. (The Milesians were also empiricists, but they simply took their empiricism for granted and apparently did not reflect on, or write about, it.) Xenophanes' reliance on empiricism led him to draw some strong conclusions about the limits of human knowledge. He argued, in fact, that we cannot have any knowledge when it comes to the important realms of religion and science; the gods, the question of physis, and the developing cosmos are all outside the range of our experience. Since we cannot observe these phenomena, argued the empiricist Xenophanes, we cannot have any knowledge regarding them. All that we can have are beliefs. This distinction between knowledge and belief has become one of the most important themes in philosophy.

        Both Heraclitus and Parmenides attempted to escape Xenophanes' skeptical conclusions by recommending methods of inquiry that go beyond experience. Heraclitus developed his idea of the logos, the pattern or law that underlies all of nature. The logos of the world, he claimed, has a counterpart logos in our souls, which enables us to decode and understand nature. In other words, we should not try to arrive at knowledge through mere observation, rather we should try to rationally understand the structure of the world, using our own internal faculty of reason. To try to arrive at knowledge without understanding the logos, he claims, is like trying to decipher speech without understanding the language.

        Parmenides also stresses the importance of pure reason in arriving at knowledge. In fact, he believed that human beings should ignore their sensory experience of the world entirely. Whereas Heraclitus claimed that observation needed only to be tempered by rational insight in order to lead to knowledge, Parmenides believed that any observation at all was bound to lead to untruths. Using only his faculty of reason, he arrives at a picture of the world that is wholly unlike anything we could possibly arrive at through observation. The world as it really is, on this picture, is nothing like the world that we can observe. The only way to arrive at knowledge, then, is to reason logically. Observation has nothing at all to do with the enterprise.

         


        • Lecture 4. Early Greek Philosophy

          Thales of Miletus

          Introduction

          Thales was born in the city of Miletus in Ionia around 685 B.C. He was a well- known public figure in his day and was included on most lists naming the Seven Sages of Greece. It seems that his fame was not only due to his theoretical achievements, but also to more practical triumphs. Among his accomplishments he could count military engineering (he redirected the flow of a raging river so that King Croessus's army could cross), geometry (he devised a means of measuring the height of the pyramids and the distance of ships at sea using triangulation), and astronomy (in 585 B.C., using his astronomical knowledge along with the Babylonian tables of lunar and solar orbits, he was the first man to correctly predict a solar eclipse). He also wrote a guide for mariners and managed to amass a fortune by using his astronomical theories to predict the appearance of a large olive crop and then buying up all the olive presses in the surrounding area (the sole aim of this latter exploit, supposedly, was to prove that philosophers can make money if they want to). In between these various activities Thales also found the time to develop the first known philosophical system. Unfortunately, no fragments of his original writings have survived to the present day, and all that we know about his thought boils down to five statements found in Aristotle. From these five statements we can identify four basic tenets of Thales' world view: (1) The world derives from water; (2) The world rests on water; (3) The world is full of gods; (4) Soul produces motion. Aristotle offers up even these snippets very hesitantly, suggesting that even by his time Thales was known only by report and not through any first-hand evidence.

          The World Derives from Water (fragment A12)

          With this notion, Thales ushers in the single most important preoccupation of the Presocratics: the problem of physis. In its most robust form, the physis problem is a search to identify that thing out of which all else is derived and will ultimately return (the source or origin of the world), as well as that thing of which everything else is a variation (the unifier within nature). In Thales', as far as we can tell from the evidence, his physis—water—only fulfills the first of these functions. Water is the substance from which the entire cosmos emerged (and perhaps also to which it will return). Whether or not it is also the unifier within nature is impossible to determine, since we have no evidence that bears on the issue. Everything in the world may be a variation on water according to Thales, or it may not.

          The claim that there is a single substance out of which everything else derived is commonly referred to as material monism: material because it claims that the source of all nature is something physical (as opposed to, say, something mental), and monism because it posits that there is only one such thing. Thales is the first of a long line of material monists, extending all the way to the present day. The notion that the whole universe emerged from primeval water was a common theory in Near Eastern and Greek mythology, so Thales' idea is not original in this sense. What is original about the idea, though, is that Thales' claim is about water as a natural phenomenon and not about water as some personified god or goddess. In addition, Thales seems to have provided rational arguments for his water-centric view. According to Aristotle, Thales turned to biology in order to understand how the universe was produced. In the biological world he observed three things: first, he observed that all life depends on water. Give water to a plant and the plant will survive, remove the water and it will whither and die. This was, similarly, the case for all animals. Further he observed that seeds, the source of most life, are themselves moist. Finally, he observed that even heat (in the form of the sun and moon) is generated out of moisture and kept alive by it (apparently this last bit of data was based on the relationship he observed between heavenly bodies and the oceans). Observing that life springs from water in the biological sphere, he concluded that the same must hold true of the entire universe.

          Hippolytus gives another possible line of reasoning that might have convinced Thales. Water, alone among the natural elements, can take form of a solid, a liquid, or a gas. He claims that Thales noticed that, "As the water solidifies, things acquire firmness, as it melts their individual existence in threatened."

          What seems most likely is that Thales' first formed the notion of a water- derived world from the mythological water cosmogonies and that he then turned to these confirming instances in biology and proto-chemistry for support.

          The World Rests on Water (fragment A14)

          The notion that the earth floats on water was a commonly held mythological belief, and it is not clear that Thales' himself held it. Some commentators have argued that the attribution of this belief to Thales' is the result of confusion about his real claim, which was that the world derives from water. The question of the world's support, though, is one that the other Milesian philosophers address, and so it seems likely that Thales addressed it as well and that this was his answer.

          All Things are Full of Gods (fragment A22)

          Thales' claim that all things are full of gods, should not be read as a confirmation of the mythological idea that the supernatural gods control nature. Instead, we can read this claim as the natural consequence of the view that all things derive from water. Thales almost certainly identified water as something divine (all the Presocratics seemed to identify their physis with divinity), and so everything in the world, as derivatives of water, would have a divine element to them.

          Though Thales believed that water is divine he did not believe that water had human motivations, wants, desires, or even any interest at all in human society. Water was probably just divine for him in the sense that it was the source of the universe and perhaps also in the sense that it was the guiding or controlling force in nature. additionall The claim that all things are full of gods might also be read as saying something slightly more substantive than that all things derive from divine water: it might be read as the claim that even inanimate objects are ensouled or alive in some sense, perhaps because of their connection to water. In what sense these things should be seen as alive, becomes clear in the final piece of evidence we have for Thales' thought.

          The Soul Produces Motion

          The claim that the soul produces motion seems to be an attempt to equate being alive, or having soul, with motive power. Taken together with the previous statement, we might conjecture that the property of being motive (i.e. being alive) derives from having some share in divinity (a share which all objects might automatically posses simply because they derive from water). This would certainly complement theories of some later Presocratics, including the two other Milesian philosophers who do seem to explicitly hold that eternal motion is part and parcel of divinity.

          Thales, apparently in connection with this statement, pointed as evidence to the case of magnets. Magnets are inanimate objects, and yet they have the power to move iron. If even magnets have motive force, he seems to be arguing, then all things probably have motive force, hence all things are ensouled.

          It seems very likely, from the evidence of this example, that the two claims—(1) all things are full of gods, and (2) the soul produces motion—are connected. Why would Thales be concerned to prove that inanimate objects have motive force (i.e. are ensouled) if he did not want to prove that all objects are ensouled? And if he did want to prove that all objects are ensouled, it seems plausible that this is, at least in part, what he meant by the claim that all things are full of gods (especially since soul and motive power seem to be intimately connected to divinity in the systems put forward by other Presocratics).

          Anaximander of Miletus

          Introduction

          In all likelihood, Anaximander was the student of Thales. He was born around 610 B.C., also in Miletus. Like his teacher, his main interests were in natural philosophy, geometry, and astronomy. Also like his teacher, he was apparently a very busy figure; reports tell us that he was the first man to construct a map of the known world, the first to build a sundial, and the first to build a celestial globe with a chart of the stars.

          Anaximander was a material monist, but the physis he posits is much more conceptually sophisticated than that of Thales. The evidence we have for him provides a slightly more thorough picture of his thought. Among the many impressive bits and pieces, we can find the first use of the famous principle of sufficient reason and what appears to be the first statement of evolutionary theory.

          The physis is the Unbounded

          In Thales' system water was supposed to be the source out of which everything arose. In Anaximander's system the Unbounded (or apeiron) is both the source out of which everything derives and also the unifier within nature. That is to say, in Anaximander's worldview, everything in the universe is in fact just a variation on the Unbounded.

          As a physis, the Unbounded has many theoretical advantages over water. As Anaximander no doubt reasoned, the water theory leads to a real problem for the existence of fire. If everything derived from water (and especially if everything still is water in some sense), fire could not possibly survive. In order to allow for the existence of all of the opposites, Anaximander decided to make his physis indefinite, having no particular qualities of its own. Because the Unbounded is entirely neutral between opposites, it does not pose a threat to any of them.

          This is clearly a major conceptual step forward. Anaximander has separated his explanatory entity from the entities that need explaining—always a good first step in any explanatory enterprise. He has posited, in fact, the first theoretical entity—an entity that we cannot observe, but that whose existence we infer because of its explanatory role.

          In addition to being indefinite, the Unbounded is also limitless or infinite, both temporally and spatially. The Unbounded must be limitless because it must be inexhaustible in order to give rise to everything else in the universe. It must have unlimited potentialities.

          In Thales' system we saw hints that water was divine; here we get an explicit statement identifying the Unbounded with divinity. The Unbounded, we are told, is divine because it is deathless and indestructible. This can be read in two ways. Either being divine simply consists in being deathless and indestructible, in which case the Unbounded is divine by default, or else being deathless and destructible are simply two symptoms of divinity, and being divine actually consists in something else. What else it could mean to be divine is unclear. Perhaps the Unbounded is divine in the sense of being the ultimate motive force. Certainly motion is an important property of the Unbounded.

          The Generation of the Cosmos

          In Thales' thought, we saw the emergence of the first Presocratic preoccupation: the physis problem. With Anaximander we see the emergence of the other two: the plurality problem and the maintenance problem. The plurality problem asks how the single physis could have given rise to the multitude of objects that populate our cosmos. The maintenance problem asks how the cosmos manages to remain relatively stable and predictable.

          In answer to the question of plurality, Anaximander posits the following picture: The Unbounded moves with eternal motion (because it is alive, remember the important principle from Thales identifying life with motive force). As the Unbounded moves, something separates off from it. From this something, in turn, hot and cold separate off. Hot becomes fire, which then forms the sun and other heavenly bodies. Cold becomes dark mist which then forms earth and air, both of which originally moist but are dried off by fire.

          (Though hot and cold get the generation of the cosmos going, they are not the only opposites with importance in Anaximander's system. Wet and dry are also invoked a lot too. Opposites are, without a doubt, the most important forces in the system.)

          When reading about these opposites, such as hot and cold, it is natural to wonder whether they are meant to be qualities or substances. Unfortunately, this distinction is post-Socratic, and so the truth is probably nothing so concrete as either of these extremes. It is best, therefore, to simply think of hot and cold (and moist and dry, and all the other opposites) as forces, or agents of physical change. These forces are present in varying degrees at different places in the cosmos at all times.

          The next obvious question to ask, of course, is how the opposites are related to the Unbounded. We know that they somehow come out of it, but does that mean that they were originally in it? There are several possibilities, two of which are ventured by Aristotle. The first possibility is that the Unbounded really is a mixture of all opposites, and the second is that the opposites are simply modifications of the Unbounded. If the first reading is correct, then the fact that the Unbounded possesses no qualities of its own seems threatened. In fact, the first reading makes it seem as if there is not a single physis, but rather an infinite number (i.e. every possible opposite), a reading that some have adopted. The second reading is troubling for another reason: if the opposites are not within the Unbounded originally, it is entirely unclear how they ever arise from it. This seems to be the problem that Anaximander's student Anaximenes seized upon.

          Anaximander does at one point describe a vortex motion (dine), in which heavier pieces of the Unbounded settle and lighter pieces fly upwards, but this mechanism is meant explain the separation of the cosmos into heavier and lighter components, as well as the rotation of heavenly bodies. It is never connected to the separation of opposites from the Unbounded, nor is it at all clear how it would help to clarify that matter. We are left without any significant clues, therefore, to help us answer the question of how the opposites are related to, and arise from, the Unbounded.

          The Unbounded Steers all Things

          The opposites are not only crucial to Anaximander's answer to the plurality problem, they are also crucial to his maintenance hypothesis. The lawful state of the world, he believes, is one of equilibrium or balance between opposites. Nature itself, through the governance of the Unbounded, maintains this equilibrium through a mechanism he analogizes to human law courts.

          The picture is apparently supposed to go like this: The opposites are continually struggling against each other for dominance. In what sense they are struggling is not clear. Most likely, they are transforming into one another, and thereby destroying one another. The Unbounded steps in and restores the proper balance between them, making them "pay penalty and retribution." The cycles of night and day, and of the four seasons, are perfect examples of the forced equilibrium, and probably the examples Anaxagoras himself had in mind.

          The Unbounded, then, is the natural manifestation of physical law, imposing a lawfulness upon continually struggling opposites, and thereby maintaining an equilibrium within the cosmos.

          The Earth Stays Up Because of Symmetry in the Cosmos

          The inherent equilibrium in the cosmos is also responsible for supporting the earth. Unlike his teacher Thales', who believed that the earth was supported by water, and his student Anaximenes, who believed that earth floated on a cushion of air, Anaxagoras was the first to maintain that the earth needs no material support. The earth, he claims, is at rest because it is perfectly balanced within the cosmos. The whole cosmos is symmetrical, with the earth right in the middle. There is no reason, therefore, for it to move in any direction, including down.

          In proposing this line of reasoning, Anaximander is the first to make use of an important philosophical principle, most closely associated with the great eighteenth century philosopher G.W. Leibniz: the principle of sufficient reason. The principle of sufficient reason states that there is no effect without a cause, or rather, that nothing happens unless there is a reason for it to happen. Because the earth is equidistant from every part of the cosmos, Anaximander argues, there could be no reason for it to move in one direction rather than another. Therefore, it does not move at all.

          Anaximander paints an interesting picture of this perfectly symmetrical cosmos: heavenly bodies are in fact wheels of fire, surrounding the earth. We see only small glimpses of these fiery wheels because we are cut off from them by an opaque air. Within this opaque air, though, are small vents, which afford us a view of small pieces of the fiery wheels. An eclipse occurs, on this view, whenever a vent becomes clogged, blocking our view of the sun wheel.

          Evolutionary Theory

          Perhaps the most startling aspect of Anaximander's thought is his proto- evolutionary theory. Anaximander seems to have anticipated Darwin by over two millennia. He observes that human beings have a long childhood during which time they are heavily dependent on others for their survival. Given this long dependence period, he wonders how the first human beings could have survived, since there would have been no one around to care for them. He reasons that human beings must have evolved from a fishlike creature, since fish have no period of dependence. Modern evolutionary theory agrees with Anaximander; in all likelihood the first animals were fishlike creatures.

          Anaximenes of Miletus

          Introduction

          Anaximenes was another resident of Miletus, the last of the Milesian philosophers. He was the student of Anaximander, though he is generally seen as taking a step backward from his great mentor. His one significant accomplishment was that he was the first person to propose a mechanism by which the physis (in his case, a misty air) transforms into the plurality of objects we see around us in the observable world.

          The Physis is Aer

          Like Anaximander's Unbounded, Anaximenes' aer is unlimited and inexhaustible. Aer, however, is definite. It is something like mist, a breathy thing. Anaximenes arrives at his physis by observing living creatures. What makes a creature alive, he observes, is that it breathes. A breathy thing, which he calls soul, both holds together and guides the living creature. There must be some similar element, he reasons, that performs that same function for the whole cosmos. An argument of this form, which reasons from the human being to the whole cosmos, is often called a microcosm/macrocosm argument. It was used frequently in ancient Greek medicine, but this is its first appearance in natural philosophy.

          Most commentators view Anaximenes' choice of aer for physis as a big step backward from Anaximander's Unbounded. After all, the Unbounded had the advantage of being dissociated from the changing elements that it was supposed to explain. But it is not that hard to see why Anaximenes might have believed that his physis was superior to the Unbounded. First of all, aer is not just a theoretical entity; we have a reason to believe it exists, and we can even observe it. In addition, it is not so nebulous and vague a substance, and so we can better understand its connection to the objects around us; we can conceive of how it gave rise to the opposites, whereas with the Unbounded it is difficult to understand how something with no qualities can act as the source of all the qualities in the world. Anaximenes is able to give us an account of how his physis gives rise to the plurality, something that Anaximander, presumably, would have been hard-pressed to do.

          Rarefaction and Condensation

          Anaximenes is the first to explicitly include the processes by which his physis is transformed into the plurality of observable objects. Like most other processes the Milesians proposed, this one involves the eternal motion of the physis. As aer moves it can either become rarefied or condensed. When rarefied, aer becomes fire. When it condenses just a little it becomes wind. Condense it more and it becomes water, more and it becomes clouds, then earth, and finally, in its most condensed form, stone. In this way, Anaximenes is able to derive all the qualities in the world out of quantity. (By laying out all of these familiar substances in series, Anaximenes makes an important advance: he shows that the elements of the world are not separated by qualitative gaps, but that they instead form a continuity.)

          It is tempting to view the process of rarefaction and condensation in the mechanistic terms though which we understand these processes. It is unlikely, though, that Anaximenes' believed his process to involve particles moving further apart and closer together. It is not impossible, though, and if this is the case then he can be viewed as a proto-atomist.

          Like a good Milesian, Anaximenes provides us with evidence for the claim that rarefaction and condensation of air can give rise to qualitative changes. In particular, he provides us with evidence that condensation gives rise to coldness, and rarefaction to heat. His first piece of evidence comes from human breath. If we hold our lips far apart and breath out, the resulting breath is hot. If, on the other hand, we purse our lips, forcing the air into a smaller space, the resulting breath is cool. As another confirming instance, Anaximenes points to water, snow, and ice. Water, the most condensed form of the three, is warmest, ice coldest, and snow somewhere in between.

          Earth Rests on Air

          As with his identification of aer as the physis, Anaximenes takes a step backward when it comes to the question of earth's support. Earth, Anaximenes claims, rests on a cushion of air. Because earth is flat, it covers this air like a lid and cannot be budged by wind.



          Xenophanes of Colophon

          Introduction

          Xenophanes was a phusikoi in the Milesian tradition, but he is not counted among the Milesians because he was not actually from Miletus. He was born instead in Colophon, not far from Miletus, around the year 570 B.C. After Colophon fell to Medes, Xenophanes left the city, becoming a wandering poet and philosopher. It is not known exactly where he traveled, but it seems likely that he visited southern Italy at some point, since he is clearly familiar with the Pythagorean doctrine of the transmigration of souls. In addition, some historians claim that he was the teacher of Parmenides, who was himself a native of southern Italy.

          Xenophanes' interests were varied. He apparently wrote on purely poetic matters, even authoring a work on how to prepare for a drinking party (symposium), but he was also very interested in natural philosophy and religion. He was adamant in rejecting the Olympian account of the gods, insisting instead that there is only one, non-anthropomorphic god who is unmoving, but all-seeing, all-hearing, and all thinking, and who controls the universe with his thought. It seems plausible that his theological views were in a sense similar to the theological views of the Milesian philosophers, who all seemed to attribute some sort of divinity to their physis. Xenophanes is primarily of note because he was the first philosopher to explore the epistemological (i.e. having to do with knowledge) implications of the new philosophical mode of investigating the world.

          Physis as Water and Earth

          Unlike the Milesian material monists, Xenophanes posited two physis. Unfortunately, not much evidence regarding his natural science remains. It is entirely unclear why he chose these two elements as his physis.

          Xenophanes' Theology

          Most of the evidence we have regarding Xenophanes' thought involves his attack on the traditional view of the gods. He is especially concerned to prove that the traditional conception of divinity is the result of the human tendency to project our own nature onto the gods. Each of the different races, he points out, believes that the gods look like them (e.g. the Egyptians claim the gods are flat-nosed and drak, the Thracians claim the gods are blue-eyed redheads). In addition, Homer and Hesiod attributed all sorts of human personality flaws to divinity. If animals could draw, Xenophanes jibes, then horses would draw gods that look like horses, and oxen would draw gods that look like oxen.

          Two fragments show Xenophanes explaining away supposed divine beings in natural terms. The being that the Greeks call Iris, the messenger goddess, is nothing but a cloud, and the weird lights that can be seen from sea, which have been traditionally been explained as twin gods, are also clouds.

          Xenophanes' attack can be seen as an expression of the philosophical break with the poetic, mythological tradition. The philosophers are not atheists, but they do not believe in anthropomorphic gods who concern themselves with human affairs and society. What, then, do they believe in? Xenophanes, at least, believes in one god who controls the world with his thought. This god does not move physically (though probably he is within the physical world, perhaps in the form of the two physis) but all of him sees, thinks, and hears. This God might be something like rationality within nature, much like Hercaclitus's logos or even Aristotle's final cause or teleological principle.

          The Limits of Human Knowledge

          In overturning divine authority and poetic license for rational thought, the Milesians turned single-mindedly to the observation of evidence. They were unreflective empiricists, gathering all their knowledge through experience, collecting the data to be explained. Xenophanes follows in this empiricist tradition, but he is reflective about it. In particular, he notices that it has some dire consequences for the possibility of human knowledge.

          When knowledge came from divine authority, the limit of knowledge was just the limit of what the gods wanted to reveal, or the limit of what the imagination could drum up. The philosophers have hit now on a new, improved method of obtaining knowledge: investigating the world for themselves. The only problem, Xenophanes purports to show, is that this method does not actually yield much knowledge; the best it can yield is true belief. This is because most subjects of investigation—the gods, the physis, the derivation of plurality from unity—cannot be observed. These matters go beyond our experience. If the only way to obtain knowledge is to gather data with the senses (which Xenophanes believes it is) then we cannot obtain knowledge about the most important things, theology and science.

          In addition, Xenophanes points out, we can even disagree about what is directly perceived. As Xenophanes says, "if god had not created honey we'd say figs are much sweeter" (fragment 21B38). In other words, there is a high degree of indeterminacy to our perceptions, a subjective element in all of our observations. We do not gain access to the true nature of, say, the fig by tasting it. Rather, our perception of the taste of the fig varies with our other experiences. If we have tasted honey, then the fig does not taste so sweet; if we have not tasted honey, then the fig tastes very sweet to us. There is, in other words, a veil of appearances or perceptions that we cannot go beyond in our experience; all that we have access to is our own perceptions and these are subjective: they do not accurately reflect the objective reality of things.

          Since we rely on experience to give us knowledge, and experience lets us down in these two ways (first, by not even extending to the most important subjects, and second by denying us access to the real, objective nature of things) we are doomed to be forever without any real knowledge. Xenophanes' final analysis of the human capacity for knowledge is as skeptical as it could be.

          Heraclitus

          Introduction

          The Milesians and Xenophanes all assumed that there was only candidate available to take the place of divine authority and poetic inspiration: straight empirical observation. As we just saw, the reliance on straight empirical investigation lead Xenophanes to conclude that real human knowledge was impossible in most fields of inquiry; if all one has to go on is observation, then where direct observation is unavailable, knowledge is impossible. Probably in response to this pessimistic conclusion, Heraclitus was the first thinker to propose an alternative to straight observation. He presents an epistemological theory of tempered empiricism, arguably much like the method of inquiry we use in science and philosophy today. According to this picture, observation is still important in the search for knowledge, but reason allows the observer to go beyond the observational given. This epistemological theory is tightly connected to Heraclitus's interesting metaphysics, according to which the world is ordered, guided, and unified by a rational structure, a single divine law, which he calls the "logos". Matching the divine cosmic logos, happily, is a logos that resides in each of our souls. Our private logos (presumably something like our faculty of reason) allows us access to the divine logos, and thus reopens the possibility of human knowledge. Observation without an understanding of the logos is useless, but observation coupled with an understanding of the logos yields true knowledge.

          Heraclitus was born in about 540 B.C. to one of the aristocratic families of Ephesus, near Colophon. His noble birth brought with it an important hereditary role in the life of the city, a position that involved responsibilities as both a political and religious leader (for instance, he would have been in charge of supervising the city's official sacrifices). Heraclitus, however, had no interest in the political life, nor in traditional religion, and he handed over his hereditary ruling position to his younger brother. Throughout his life, and well after his death, Heraclitus had a reputation as a misanthrope and as a deliberately obscure thinker. His reputation as a misanthrope was probably based reasonably on the unkind words he had for other philosophers and historians (he called everyone from Homer to Xenophanes an ignoramus, which they technically were according to this theory of knowledge). His reputation as an obscure thinker, on the other hand, is probably unjustified. Though his lists of paradoxes might seem obscure on their surface, it is only because they are only intelligible when seen in their connection to the logos.

          The Logos

          The basic tenet of Heraclitus's system is the claim that there is a rational structure to the cosmos and that this rational structure orders and controls the universe. The logos is Heraclitus's physis but only in the sense of a unifier in nature: a fundamental part of understanding the logos involves seeing that all things are unified in it. The logos, however, is presumably not the material out of which everything else arose, though it is the origin of all things insofar as it is the arrangement of all matter.

          Heraclitus often refers to the logos as the mind of God, though it is not clear what implications this has for his theory. Probably, Heraclitus simply identified the logos with the mind of God because it is the controlling, rational force within nature. Certainly he does not view the logos in any sort of anthropomorphic terms, and it is an entirely natural, rather than supernatural, force. In addition, the logos exists squarely within the physical world. Oddly, Heraclitus seems to view the logos as part of the world in the same sense that water or air is a part of the world. It is as if he is treating the recipe as one of the ingredients.

          The logos is not only the basic concept of Heraclitus's metaphysics, it is also the basic principle of his epistemology. It is only though understanding the logos that we can make sense of our experience. Though the logos is an independently existing truth available to all (a fact which he underscores by speaking about a logos in each human soul), most people fail to recognize it. In two highly vivid metaphors, Heraclitus describes the folly of those multitudes who attempt to investigate nature without understanding the logos. He compares these people first to sleepers; like sleeping minds, the mind that does not understand the logos cannot receive information from the outside world. What goes on in a sleeping mind is purely subjective and is not connected to what is going on in the real world. Similarly, those who investigate nature without understanding the logos only gain access to their own subjective worlds, not to the real, objective one. (It is interesting to view this metaphor in relation to Xenophanes' claim about the inherent subjectivity of sensory perception).

          Later, Heraclitus also compares these same people to barbarians—that is, to people who do not understand the Greek language. When you do not understand a language, Heraclitus is telling us, all that you hear in the words is noise; you cannot discern the underlying order, the meaning of these words. In our experience of the world we are confronted with something like a language, and most people fail to make sense of this language because they do not understand the logos (which is the language of nature). Therefore, to these people (among whom he counts all previous philosophers and poets) observation is nothing but meaningless noise. We cannot, in other words, simply gather facts as the Milesians and Xenophanes tried to do, but rather in order to obtain any knowledge from these facts we must understand how they relate to the logos.

          All Things are One

          A fundamental part of the insight that allows us to make sense of experience is seeing how all that is known constitutes a unity.

          There are several ways to make sense of the claim that all things form a unity. It is tempting to read this claim as a statement of material monism. If Heraclitus is a material monist, then the original material out of which everything else derives on his picture, is, doubtless fire. He speaks about fire a great deal, referring to it as the principle of wisdom and the material manifestation of the logos. Since the logos is only the physis in the sense of being the unifier in nature, perhaps fire, its material manifestation, is the physis in the sense of the material from which everything arose.

          But though it is tempting to believe that Heraclitus was a material monist with fire as his physis, it seems unlikely. Fire seems like more of a metaphor for the logos (as we will see below) than its actual material manifestation. In addition, there are no fragments that directly link fire to the originating substance of the world.

          A more likely interpretation of Heraclitus's claim that all things are one focuses on the paradoxes he presents rather than on his statements concerning fire. The paradoxes of opposites that Heraclitus presents fall into three broad sorts: First there are several paradoxes that seem intended to alert us to the co-existence of opposites. So, for instance, he points out that the same ocean water can be undrinkable and dangerous to us but drinkable and life sustaining to fish. The next bunch of paradoxes seems to point to a stronger relation between certain opposites, a metaphysical and conceptual dependence (i.e. they cannot exist, and cannot even be thought of, without one another). The road up and the road down, he points out, are the same road. One cannot exist without the other, nor can we think of one without thinking of the other. Similarly, night and day are dependent in this way. There would be no night without day and vice versa. Finally, in the last bunch of paradoxes, we get the strongest sort of relation, a relation of identity. God (or the logos), he tells us, is both night and day, winter and summer, war and peace, satiety and hunger.

          It is this relation of identity between opposites that Heraclitus is probably referring to when he claims that all things are one. All things are one, because all opposites form a unity through their connection to the logos. Through all of the daily, seasonal, social, and other cycles, unity is maintained because everything is a part of the divine law of the logos. It is this fact—the unity of all things through the logos—that we have to understand if we are going to make sense of our experience. In the search for knowledge, in other words, the first step is to come to grips with the fact that what seems to be a clash of opposites is really just the unity of a rational pattern.

          All is Flux

          Like all of the Presocratics, Heraclitus is sure that there is an equilibrium in nature, some constant state that gets maintained, but unlike the others he believes that the equilibrium state is a state of constant flux. The cosmos is a place of constant change, with a hidden underlying stability in the form of the divine law according to which all change takes place. Returning now to the idea of fire, we can understand why Heraclitus identifies that substance as the most fitting metaphor for the logos: fire is a substance of constant change. It is for this same reason that Heraclitus likens the cosmos to a river; a river both constantly changes, as new water continually flows through, and remains the same (we continue to call the Rhine the "Rhine" from moment to moment).

          In this part of his theory, Heraclitus can be seen as expanding Anaximander's idea of the interaction of opposites and the resulting equilibrium, only with a new twist all his own. On Anaximander's worldview there was occasional strife and then a return to equilibrium through the imposition of justice on the part of the Unbounded. On Heraclitus' view, on the other hand, strife between the opposites is universal; it never ceases. In fact, it is because of strife that we have justice and equilibrium. While for Anaximander strife was beyond the plan and justice had to step in to regulate it, for Heraclitus strife is the plan.

          Heraclitus's idea of strife between opposites does not have any obvious meaning for modern readers. In all likelihood it refers to the constant oscillation between the opposites. Again, the daily and seasonal cycles, in which one opposite is continually destroyed into the next, would be the prime example of this sort of strife. But strife could also be a mere tension between opposites, or the constant encroachment of one opposite upon the others. Regardless, the main thing to take away from Heraclitus's theory of equilibrium is that change and strife are the norm, not the aberrations.

          Parmenides of Elea

          Introduction

          After almost a century of philosophy based on the general Milesian pattern Parmenides cast the whole project into doubt by maintaining that the fundamental nature of reality has nothing to do with the world as we experience it. He went much further than Heraclitus in tempering our reliance on the senses; he rejected the senses as entirely misleading and pressed on reason alone to reveal the truth. Through his use of unadulterated reason he came to conclusions about the nature of the world that seemed to suggest not only that the theories of earlier thinkers were utterly unintelligible, but that the very questions they asked were the wrong questions to be asking. In so doing, he entirely changed the course of philosophy, demanding new attention for fundamental problems (such as the problems of change and plurality) and setting the standard for a new, more exacting level of rational argument.

          Parmenides was born in 515 B.C. in the city of Elea in southern Italy. There are reports that he was a student of Xenophanes, and it seems plausible that his work was in part a reaction to Xenophanes' pessimistic epistemology. There is also some speculation that he was associated with the Pythagoreans at one time, since they, like he, were based in southern Italy. But, if this is true, then he completely rejected their influence.

          Like Xenophanes, Parmenides wrote in verse. His poem "On Nature" is in Homeric hexameters and includes many Homeric images, especially from the Odyssey. With obvious reference to the poetic tradition, Parmenides begins his poem with the invocation of a divine source. Where the poets would invoke the muses in order to give themselves authority, Parmenides opens by describing a similarly fanciful scene: he is taken in a chariot to meet a goddess, who tells him that she will teach him all things about the nature of reality and assures him of the certainty of what she is about to reveal. But, she adds in a philosophical twist, he must still assess for himself all the arguments that she presents. Parmenides' use of this old poetic, mythological ruse might have been more than literary reference. Given that Parmenides was about the put forth what might well be the single most radical and counterintuitive worldview on record, it was probably not a bad idea on his part to bolster his credibility with an appeal to divine authority.

          Putting all of his faith in the power of abstract reason, Parmenides argues in his poem that genuine knowledge can only involve being, and that non-being is literally unspeakable and unthinkable. Using only the premise that "what is" is and what "is not" is not, he proceeds to deduce the nature of reality. The reality he arrives at bears no resemblance at all to the world we experience around us through our senses.

          The Paths of "What Is" and the Path of "What is Not"

          According to Parmenides, the senses are entirely deceptive, and reason alone can lead us to truth. The nature of the world, then, can only be gotten at through a rational inquiry. When starting out on a rational inquiry, according to Parmenides, there are only two logically coherent possibilities: either you begin your inquiry with the premise that the subject of your inquiry exists or you begin with the premise that it does not exist.

          But the second of these possibilities, according to Parmenides, is utterly meaningless. It is, therefore, not a real possibility at all. Parmenides bases this claim regarding the path of "it is not" on the assertion that, "that which is there to be thought or spoken of must be" (28b6). What he seems to be getting at here is an idea that has had extraordinary pull for philosophers through contemporary times: one cannot possibly refer to what is not there to refer to.

          To understand why Parmenides and many since him have been drawn to this position, compare thought or speech to sight (this line of thinking is not only illuminating, it is also the very line of thought that often leads philosophers to make the claim in the first place): Imagine trying to see something that is not there to be seen. It is impossible. It is true that Hamlet could see a dagger even though there was no actual dagger before him, but there was a hallucination to see. Imagine if there were both no dagger and no hallucination. The he would not see anything at all.

          Well, reasons Parmenides (though not, of course, with Hamlet in mind), why should speech or thought be any different? We cannot see what is not there to be seen, so why should we be able to refer to what is not there to be referred to? If something does not exist, in other words, we cannot think about it and we cannot speak about it.

          The Third Path

          Because of this profound link between thinking and being, Parmenides claims we cannot make any statements of non-being. So we cannot, for instance, speak about unicorns, even to say that they do not exist. In fact, we can never claim that anything does not exist, because anything that does not exist cannot be spoken about.

          Certainly, it puts a strain on science and everyday chitchat to rule out all statements on non-being, but, actually, Parmenides wants to go much further than ruling out talk of unicorns. He is not only ruling out the path of not being, he is also ruling out the third path—the path that mixes both being and not being. The third path is the path that human beings generally travel, the path that the senses pull us down. Statements of the third path include such innocuous sounding claims as "the Sun is hot", "the sky is blue", and "cats are soft." To say that the sun is hot is also, implicitly, to say that it is not cold or lukewarm. To say that the sky is blue is to implicitly assert that it is not any other color. To say that cats are soft is to implicitly claim that they are not rough or sticky or hard. To make any claims about qualities, about changes, about almost anything at all, is to implicitly and illegally talk about non-being.

          The Parmenidean Real

          Parmenides thus drastically restricts the rational inquiry through which one can get at the nature of reality; this rational inquiry cannot make use of any premise that involves non-existence. The rational inquiry must begin with the premise "it is" and deduce the nature of reality from out of it. What Parmenides ends up deducing is that "what is" is ungenerated and unperishable, unchanging, perfect, one, and continuous.

          The general form of argument he uses for each of these conclusions is along the following lines: whatever is is X, because if not X then it is not-X, and in order to explain what it is for anything to be not-X we must talk about "what is not". Since we have already seen the meaninglessness of any thought or statement involving "what is not" we can conclude that whatever is is X.

          To see how this argument works in specific cases we can look at how Parmenides argues against the possibility of generation, destruction, and change. To argue against generation, Parmenides claims that there is implicit non-being in birth since it implies prior non-existence ("I will not permit you to say or to think that it grew from what is not for it is not to be said or thought that it is not" 28B8) Though Parmenides does not actually lay out a similar argument against the possibility of destruction, it is generally assumed that this is because he sees it as obvious that a parallel argument can be given—just as generation must be generation out of non-being, destruction must be destruction into non-being.

          The impossibility of change follows from the impossibility of generation since characteristics and properties cannot come into being any more than objects can. To say, e.g., 'X is becoming rarified' implies that there was a time when X's rarefaction did not exist.

          In addition to being eternal and unchanging, Parmenides also deduces that the Real is "perfect" and that it is one and continuous. In claiming that "what is" is perfect, he seeks to show that it has definite limits and is spherically shaped. In claiming that "what is" is one and continuous, Parmenides is probably making the strong claim that all of reality is one—that is, that the class of things that exist contains just one member (rather than only the weaker claim that "what is" is all internally alike, which he undoubtedly means to assert as well). It is difficult, though, to see how Parmenides thought he could have argued for this stronger claim. One suggestion that has been made (for instance by Kirk, Raven, and Schofield on page 251 of The Presocratic Philosophers) is that Parmenides thought he had an argument for this conclusion based on the identity of indiscernibles. Such an argument might have gone as follows: in order for X to be separate from Y there must be some Z, distinct from both, separating them. Z must either be or not be. But Z cannot not be because that is incoherent. And if, instead, it is, then there is nothing to distinguish it from either X or Y since being does not admit of degrees.

          The Cosmogony

          After providing us with this startling account of reality, Parmenides (or his goddess) then does something even more startling: he gives us a full-blown, Milesian-style cosmogony. In other words, after arguing that the world as we observe it does not exist, he then proceeds to give an account of the origins of the world as we observe it. This move has confounded commentators for millennia, and though there are several theories to account for this oddity, none of them are particularly satisfying.

          The first possibility is that Parmenides provides the cosmogony as a parody. On this reading, the cosmogony is thoroughly condemned by Parmenides and is meant to appear as self-refuting. Though this explanation would be consistent with the rest of his thought, it leaves some troubling puzzles. First and foremost among these is the question of why Parmenides would go to the enormous trouble of providing a detailed cosmogony (his cosmogony is more detailed than most) if his only point was to ridicule the entire field of cosmogony.

          The other possibility, no less troubling, is that Parmenides lightens up a little at the end of his work: that he admits that there are, in fact, two levels of reality. The first is the higher, realer level that he has just described in the "On Truth" section of his poem. The second is the inferior, lower level that corresponds with our observations. This lower level of reality would not have full being, on this view, but it would also not be an utter delusion either. Some ways of describing it would be more accurate than others. The cosmogony, then, would be the best possible account of the inferior world of appearances.

          Something like this division of two worlds is what Plato presents in the Republic. According to Plato, there is a world of appearances in which human beings reside and then a more real world of forms to which human beings have intellectual access. It is possible that Parmenides anticipated Plato's division by a few decades or even that he inspired it. If he did, though, his students certainly did not follow him in this. Zeno is adamant that plurality and motion are absolutely impossible, and Melissus is just as adamant that there is only one real thing in the world. This would not, though, be the first time that the followers were more dogmatic than their leader.

          The Eleatics: Zeno of Elea and Melissus of Samos

          Introduction

          Parmenides inspired many philosophers to follow in his footsteps. The movement he founded is called the school of Elea, and its members are referred to as the Eleatics. The school of Elea was the first movement to treat pure reason as the sole criterion of truth. Logical consistency and internal theoretic coherence, rather than any sort of observational evidence, guided their entire search for knowledge. The main Eleatic positions were inherited from Parmenides: (1) there is no genesis or corruption; (2) there is no plurality out of unity; (3) there is no change; (4) it is impossible to speak or think of non-being.

          Zeno of Elea

          Zeno of Elea was Parmenides' most eminent student and was also probably his lover. He was working at roughly the same time as Anaxagoras and Empedocles, and devoted his career to devising arguments in defense of the doctrine of the Parmenidean Real. In his famous paradoxes he attempted to shows that pluralism (i.e. the idea that there really is a plurality of existing things) runs into even greater absurdities than Parmenides' doctrine. His arguments use the method of reductio ad absurdum, in which he begins with the premise he wants to deny, and then shows that this premise leads to a logical contradiction. Zeno did not view these arguments as paradoxes, since he believed that the premises he was trying to undermine (for instance, the existence of motion) were false. Since we today believe that these premises are true, (i.e. we do believe that there is motion in the world, and we do believe that there is a plurality of existing things) we find his brilliant puzzles slightly disturbing.

          Melissus of Samos

          Melissus of Samos was the last of the famous Eleatics, writing around 440 B.C. He argued for Parmenides' claims in his own original way, drawing on the distinction between "is" and "seems" and the metaphysical consequences of the former. If something "is" X, he claimed, then it must be X essentially, and so it can never not be X. So, for instance, if something is hot, and does not just seem hot, then it can never stop being hot. Since nothing retains properties indefinitely and through all circumstances, he argues, nothing really is, except the Parmenidean Real.



          Empedocles

          Introduction

          For those Presocratics who chose not to join the Eleatic camp, the new challenge was to reconcile Parmenides' rigorously argued rejection of change and multiplicity with the obviously changing and varied world of sense experience. Unlike the Eleatics, these philosophers, the pluralists, were not prepared to give up entirely on the world they saw around them, but nor could they ignore Parmenides' formidable logic. Empedocles was the first to face this challenge, and he set the model for all later attempts, by arguing for the existence of certain basic substances of the universe (in his case the four elements) that have many of the key features of the Parmenidean Real. These substances, however, can mix with and separate from each other and thus give rise to the world as we experience it without violating Parmenides' most basic demands.

          Empedocles was born in Acragas, Sicily around 492 B.C. He was a philosopher, a medical man, an active politician, and a truly flamboyant figure. He supposedly dressed ostentatiously in flowing purple robes and a gold diadem and even went so far as to call himself an immortal god. As a politician, he supported democracy, although his position as an aristocrat would have made him a likelier proponent of the oligarchy. His exploits in other fields defied expectation to an even more dramatic degree. Legend has it that he managed to keep a woman alive for a month, despite the fact that she had lost her pulse and had stopped breathing. When plague hit the city of Selinus, he managed to divert two streams and thereby rout out the illness. For unknown reasons, he was eventually exiled from his home city. He probably died soon thereafter in the Peloponese, though given his larger-than-life persona it is not surprising that more exciting stories of his death abound. The most intriguing of these, found in Diogenes Laertius, claims that Empedocles' last act was to leap into a crater of Mt. Etna in order to prove once and for all that he was a god.

          Despite his hijinks and possible madness, Empedocles was a serious and profound philosopher. Like Parmenides, he wrote in verse, and the poem that survives is dedicated to his lover Pausanius. In this work, Empedocles tells Pausinius about the nature of the cosmos, describing an original pure state from which humans have fallen and to which they may return through a process of purification involving vegetarianism. More important for our purposes, Empedocles' poem also delineates the six basic entities of the world: the four elements, earth, air, fire, and water, and the two motive forces, love and strife. According to his picture, the actions of love and strife result in cosmic cycles in which the elements mix together by love and are pulled apart by strife. These mixings and separations result in the world as we perceive it.

          The Four Elements

          Parmenides and his followers insisted that there was no change in the real world. Empedocles' response was to divide the world into the more real and the less real. On the level of the more real, there are only the four elements (or roots) and the two motive forces. Among these elements and forces there is no generation and destruction—hence, no change. The amount of, say, earth in the world remains constant, and earth never changes qualitatively. Each of the four elements and the two motive forces, then, are Parmenidean Reals.

          However, there is also, on this view, the lower level of reality. The world of sensory experience, the world we see and hear around us, belongs to this level of reality. This world comes about as a result of the mixing and separating of the four elements according to the forces of love and strife. Though there is change, generation, and destruction in this world, it is not a violation of the Eleatic demands, Empedocles believed, because these changes were not taking place on the level of the most real things.

          Empedocles described in detail how the different mixtures of his elements yielded different substances. In fact, he even explained how different mixtures sometimes yield different degrees of the same substance. For instance, the elemental recipe for blood could be varied to produce different sorts of blood, which in turn corresponded to varying levels of intelligence in the blood's owner. Qualitative diversity, on this view, is grounded in quantitative differences, much like it was on Anaximines' picture.

          Love and Strife

          In the age before Parmenides, Empedocles would not have had to posit the two motive forces. To explain why his elements mixed and separated, he would merely have referred flippantly to eternal motion. In the face of Parmenides' challenge to the very existence of change, however, philosophers could no longer take change and motion for granted. Empedocles, like those who came after him, was forced to both explain what he meant by change and to give a very specific account (by Presocratic standards) of how change occurs.

          He, therefore, posited the two motive forces of love and strife. These forces are corporeal, or physical. Their main role is to cause the elements to mix in their proper ratios. Love causes them to mix, strife to separate.

          Empedocles speaks about the motive forces as if they really were emotions. He often says that the elements yearn for each other and then come together, or that they get angered and separate. But this is almost certainly just a metaphorical way of speaking; it is very doubtful that he personified his natural world to such a degree. How exactly the motive forces were meant to work, though, if not as motivating emotions, is entirely unclear. Perhaps Empedocles did not think out his theory that far, or perhaps we simply do not have the relevant passages.

          As far as the equilibrium of the cosmos is concerned, Empedocles seems torn between the placid state of Anaximander and the fiery state of Heraclitus. The cosmos, as Empedocles envisions them, go through long cycles during which one or the other of the motive forces dominates. When the force of love is in control the universe tends toward harmony, and diversity begins fading; sometimes the universe reaches such a harmonious state that the only diversity remaining is that of the original four elements. When, on the other hand, the individuating force of strife is in control, there is tension between opposites; in this state, objects, qualities, and properties begin to increasingly individuate themselves.

          Another Instance of Proto-Darwinism

          In describing the state and operations of the cosmos, Empedocles floats a theory of the origin of species that hits startling close to Darwinian natural selection. Many species, he explains, arose early on by sheer chance, through the mixing of the elements by love. Only some of these, though, were adapted to survival. Those that were best adapted survived and passed on their characteristics to later generations. Those that were not well-adapted, simply died before propagating. His examples of maladaptive species are particularly fun to thumb through, since they read like descriptions of characters from a goofy, over-stuffed science fiction parody: neckless faces, arms without shoulders, eyes in need of foreheads, men with faces on both sides, ox-men, and androgynous beings.

          The Atomists: Leucippus and Democritus

          Introduction

          Like Anaxagoras and Empedocles, the atomists wanted to answer the basic post- Eleatic question: if change cannot occur in the real, then how does it occur in the observable world? Also like the previous two philosophers, they answered this question by postulating the existence of certain elements of the cosmos that are real in the Parmenidean sense and by claiming further that through analyzing the arrangement and rearrangement of these basic elements, we can arrive at an account of the visible world without having to admit that there is any change on the level of the real. But whereas the two previous pluralists rejected the Eleatic notion that what exists is one in kind, the atomists retained this contraint. The atomists posit just one kind of real thing — tiny, indivisible atoms, swimming around in a void. This account of reality is by far most sophisticated of all those ventured by the Presocratics, and it even comes alarmingly close to anticipating the modern scientific view of ultimate reality.

          The only two known Presocratic atomists were Leucippus and his student Democritus. Unfortunately, we know very little about Leucippus, the founder of atomic theory. Even his place of birth is in dispute, given variously as Miletus, Abdera, and Elea. What we do know with moderate certainty is that Leucippus studied with members of the school of Elea at some point in his life. He was clearly influenced by Zeno as is evidenced by his strong interest in the problems and paradoxes of space. The only other fact we know about this great thinker is that he wrote two books, no parts of which survive. The first of these was called On Mind and the second The Great World System.

          Democritus was the student of Leucippus, and he is the figure through whom atomism has been transmitted to later generations. It is not known how much of his theory is simply a repetition of Leucippus's teaching and how much of it is original to him, but it was he who brought atomism to public attention and who made it a matter of philosophical controversy. He born around 460 B.C. in Abdera, Thrace in Northern Greece, and he traveled throughout the ancient world. We are aware of the titles of at least seventy books that he supposedly authored, and these works cover a wide variety of subjects. He wrote in nearly all philosophical areas, including mathematics, natural philosophy, literature, and grammar, and also wrote more popular works, such as accounts of his travels. In addition, he seems to have written on farming, medicine, military science, and even painting. Interestingly, not only did he have something of worth to say on all of these topics, but he even applied atomic theory to most of them. He apparently believed that atomism could be usefully extended to all aspects of the world, including even ethics and politics.

          Atoms and the Void

          Like Anaxagoras and Empedocles, The Atomists claimed that there was a level of reality that satisfied the Eleatic demands. This level of reality was populated by atoms and the void. Atoms are, literally, indivisible particles, which are so small that they can be split no further. The atoms qualify as Parmenidean Reals in two ways. First, like the four elements and the homeomeric substances, atoms cannot be generated, destroyed, or qualitatively changed. In addition, they have an added level of compliance with the Parmenidean demands: the atoms themselves are one in kind. All atoms are made out of the same material. Reality, then, really is one and continuous in at least a qualitative sense.

          Though the atoms are materially homogenous (as well as being uniformly impenetrable and indivisible), they do have some variable properties. They differ from one another in shape, arrangement, position, size, and motion. It is by the arrangement and rearrangement of atoms of different shapes, sizes, and motions that the observable world comes into being.

          The boldest aspect of the atomist theory, is that, in addition to positing the atoms as Parmenidean Reals, it also posits a void, which is identified explicitly with non-being. There is an extremely good reason for this move: the Eleatics argued that (1) being cannot admit of a vacuum (i.e. empty space) and (2) without a vacuum there can be no movement. Leucippus was impressed by both of these arguments and was persuaded of their truth. However, he was equally certain of the truth of the claim that movement does in fact exist, since he saw movement all around him. Reasoning with these three premises (i.e. the two Eleatic conclusions, and his own observation that motion must exist) he concluded that there must actually be a vacuum and that this vacuum must be identified with not-being. Though the vacuum is non-being, it is nonetheless real. The atoms exist in this vacuum or void and move about in it, giving rise to the observable world.

          Unlike his Eleatic teachers, Leucippus was apparently not overly concerned about mixing the ideas of being and not-being, nor about talking about not-being. As far as we know, he did not take the further step, which would soon be taken by Plato, and make gestures at diffusing this worry, by distinguishing between grades of being and types of negation.

          The Visible World

          In order to account for the phenomena of the observable world, the atomists tell a detailed story about the coming together and separation of atoms in the void. Through their motion, the atoms collide, and though they never really touch, they form objects through their close association. The nature of these objects (and qualities) depends on the variable properties of the atoms thus joined, i.e. their arrangement, size, shape, and motion. Once again, then, what looks like generation, destruction, and change in the observable world, is really not a violation of the Eleatic demands; all that really exists in the most fundamental sense are arrangements of atoms in the void.

          Using this theory of atoms in the void, the atomists are the first philosophers to venture a full-fledged theory of sensation. They attempt to explain all of the macroscopic qualities of the world by appealing only to the size, shape, order, and position of atoms.

          An excellent example of this attempt is Democritus's account of taste. The sensations of taste, he explains, are entirely a function of the size and shape of atoms in food and their interaction with the atoms of our mouths. Sour taste, he tells us, is the result of angular atoms in twisted configurations. Sweet taste, on the other hand, is caused by rounded atoms of a moderate size. Astringent tastes come from large, barely circular atoms with many angles. Finally, bitter tastes are caused by small, smooth, round atoms, with no hooks on their surfaces. All foods, in fact, have a mixture of all of these sorts of atoms, but it is the predominant sort in the mixture that we perceive most clearly. In effect, what Democritus has done with this account, is to reduce taste to visual and tactile terms. He gives a similarly detailed account of our sensation of color, explaining this phenomenon on the basis of the size and shape of atoms, as well as the nature of the void between them.

          Nature of Atomic Motion and Physical Necessity

          The atomists give the most detailed account of the motion of their real entities. The atoms, they tell us, move by a jostling, random motion that occurs by collision. Motion, on this view, as on many later views, is transmitted upon collision.

          The motion of the atoms is eternal and involves no external forces like love, strife, or mind. Instead the motion, and all else in the physical world, is supposed to be explained by the notion of "necessity." The claim that everything happens by necessity can be seen as a very primitive (and not very well thought out, it seems) form of modern determinism—the view that every event is an effect of some prior series of effects. The order of the cosmos, then, is not imposed by some outside force on the atomist view. In modern terms we would say that order prevails in the atomist view because it falls out of the laws of nature, which govern the atoms. (Another way to put this is to say that the ultimate controlling principle in nature is that everything follows the laws of its own being.) But the atomist notion of necessity probably did not take this sophisticated a form, drawing on the concept of natural law. A more accurate description of their notion of necessity would only assert that X determines some future Y because X has the proper atoms, plus the suitable motion, to yield Y and only Y. This form of determinism is very weak, so weak that it cannot really be made to work; there is nothing else in system to explain why X would determine Y and only Y, since there is no idea of natural law.

          The explanatory weakness of atomistic determinism is probably what lead Aristotle to reject atomism despite the fact that he preferred this view to all other Presocratic theories (and even to Plato's theories in some instances). Aristotle recognized the fact that the atomists had actually removed too much anthropomorphism and that the explanatory power of their theory was thus enfeebled. They took the extra controlling force out of nature, without any real alternative to put in its stead. Aristotle put this controlling force back into the philosophical picture with his notion of final cause, or teleology.



          Anaxagoras

          Introduction

          Empedocles tried to meet the Eleatic challenge by positing four elements that were themselves Parmenidean Reals, out of which the rest of the world arose. In this way he meant to account for apparent generation, destruction, and change by arguing that these phenomena are, in fact, just the mixing and separating out of the eternal, unchanging elements. Anaxagoras follows this model, but with some modifications. In order to better account for the full diversity of objects that populate our world, he posits an infinite number of Parmenidean Reals, called the homeomeric substances. Any substance without differentiated parts, on this view, such as flesh, blood, earth, or fire, counts as a Parmenidean Real.

          Anaxagoras was born in Clazomenae in Ionia (the land of the Milesians) around 500 B.C. Like his Milesian predecessors, he was a busy public figure. For thirty years he lived in Athens, where he was the first philosopher to become a well-known teacher in the city that would soon become the hotbed of philosophy. Among his students were the dramatist Euripides and the famous Athenian politician Pericles. His association with Pericles ended up getting him in trouble; In 450 B.C. (or 430 B.C., some sources vary) he was prosecuted for impiety by the Athenian state (like Socrates and Aristotle after him), an event that was probably orchestrated by political enemies of Pericles. Unfortunately, popular outcry against Anaxagoras was heated, fueled in large part by his declaration that the sun was not a god but a hot mass of molten rock, larger than the Peloponese. He was convicted of atheism and exiled to the northern Ionian city of Lampascus, near Troy. He died there in 428 B.C.

          The Homeomeric Substances

          A common belief among ancient Greeks was the idea that like generates like. In other words, ancient Greeks believed that X comes from X. In part, this belief was fueled by the Parmenidean-inspired conviction that X cannot possibly come from not X. This principle, commonly referred to as the "like-like" principle, is in part what led Empedocles to his theory of the four elements, but it is put to even better use by Anaxagoras. Though the four elements cover some of the most basic natural kinds in the observable world, they clearly do not exhaust all worldly existents. There are many qualities that seem to have nothing to do with these four elements. Where, Anaxagoras asks, do these qualities come from?

          In place of the four elements, he posits an infinite number of Parmenidean Reals, or basic substances of existence, out of which everything else arises. In particular, he posits as the basic constituents of reality all substances without differentiated parts (homeomeric substances). A substance without differentiated parts is a substance that will remain the same substance no matter how small of large a piece of it you have. So, for instance, flesh is a homeomeric substance because a piece of flesh is just a piece of flesh no matter what size. A human body, however, is not a homeomeric substance because a piece of a human body is not the same as a whole human body. In a human body, the part is different from the whole. When it comes to bone, flesh, and marrow, on the other hand, whole and part are the same.

          Like the four elements, the homeomeric substances possess some of the crucial properties of the Parmenidean Real: They cannot be generated or destroyed, nor can they change qualitatively. Also like the four elements, the homeomeric substances can be viewed as Anaxogoras's solution to the problem of physis, both in the sense of the original material out of which everything arose and in the sense of the unifiers within nature, of which everything else is a variation.

          All Things are Mixed in All Things

          Being post-Eleatic, Anaxagoras acknowledges the fact that nothing comes into being from non-being, so he adds to his metaphysical theory the stipulation that all things are mixed in with all things. In other words, nothing comes into being from not being because there is a little of everything mixed in everything else. So, for instance, when a baby is born bald and then grows hair, that hair is not coming into being from not-being, rather what is happening is that formerly tiny, imperceptible hair parts mixed in with the scalp, are growing larger.

          Anaxagoras's theory of mixture represents a totally new move in the plurality question. Whereas the other Presocratics (Parmenides and his followers excluded) asked how a plurality could arise out of a unity, Anaxagoras bypasses the whole issue by claiming that there is a full plurality to begin with. There never really was a unity at all, since in every piece of matter, no matter how small, pieces of every other homeomeric substance is mixed in (to make this view possible, incidentally, Anaxagoras needs to hold to his principle of infinite divisibility, for which he is indebted to Zeno of Elea).

          Given that all things are in all things, it might seem that the process of identifying objects should get rather confusing, but in fact Anaxagoras has a neat solution to this worry. We identify things by the proportional amount of homeomeric substance in the mixture. Just like on Empedocles' view, objects were identified by the ratio of the four elements in their recipe, here too objects are identified by the dominant homeomeric substances in their recipe.

          Like his Milesian forebears, Anaxagoras uses his metaphysical theory as the basis of a cosmogony (or theory of the origins of the world). He paints a picture in which originally what existed was a primordial mixture containing all things. This original mixture was then set into motion, and the different parts were separated off. These then recombined with each other to produce the world as we perceive it.

          What Anaxagoras means by claiming that "all things" were in this original mixture is unclear. He probably means that all homeomeric substances were originally in this mixture, and that they were what then separated off when the motion began. This seems like the most plausible interpretation, especially given the fact that the homeomeric substances, as Parmenidean Reals, could not have been generated. Some commentators, however, have read this passage differently. Some believe that Anaxagoras meant to claim that all possible objects of the world were in this mixture, but there seems to be no reason for him to have made this strong claim. Others believe that it was only the opposites that were in this mixture, but this would then make it seem as if the homeomeric substances were generated.

          Mind

          Because of the Eleatic attack on change, Anaxagoras could not make a weak appeal to eternal motion when explaining how his original mixture got moving. To what, then, does he appeal? The confused mass gets started in the process of differentiation by the one thing not mixed in with anything else: mind or nous.

          Anaxagoras's mind is somewhat akin to Heraclitus' logos, insofar as it is the rationality that controls nature. Mind is infinite and self-ruled, and like the logos, it is very much a part of the physical world. It also, however, takes on the role of Empedocles' love and strife as the motive force in the world.

          In order to arrive at the notion of mind, Anaxagoras looks to the human analogy, drawing once again on the microcosm/macrocosm principle. In the human sphere, he reasons, when things are in confusion, it is by an activity of mind that they are set in order. The human mind sorts out the confusion, distinguishing one thing from another and putting them all in their proper place. So in the cosmos it must be a mind, which is somehow active in nature, that orders and controls. As we would expect from this analogy, Anaxagoras's mind is characterized primarily by the power to distinguish and separate one thing from another and thereby to create order in the universe.

          Anaxagoras's idea of mind probably served as the inspiration for Aristotle's notion of a final cause or telos. Aristotle bases his entire scientific enterprise on the idea that there is a purpose within nature, and that all motion can be explained in terms of the striving of each individual object to fulfill that purpose. The idea of a controlling rationality within nature, that acts as the source of all motion, first found its voice in Anaxagoras.


          Quotations, Key Words and Terms 

          Important Quotations Explained

          For it is no more fitting for what is established at the center and equally related to the extremes to move up rather than down or sideways. And it is impossible for it to make a move simultaneously in opposite directions. Therefore it is at rest of necessity. Testimonia A26.

          This passage, reported to us by Aristotle in On Heavens, provides Anaxagoras's explanation of what holds the earth steady. This account marks the first known use of the famous principle of sufficient reason, which asserts that there is no effect without a cause, i.e. nothing changes unless there is a reason for it to change. Because, on Anaximander's view, the cosmos is perfectly symmetrical, and the earth is placed squarely in its center, there could not possibly be any reason for the earth to move in one direction rather than another. Therefore, the earth does not move. Anaximander was the only early philosopher, as far as we know, to correctly claim that the earth is not supported by anything material, such as water (Thales), a cushion of air (Anaximines), or a large column (Heraclitus).

          Ethiopians say that their gods are flat-nosed and dark, Thracians that theirs are blue-eyes and red-haired. Fragment B16

          This statement is one among several of Xenophanes' clever attempts to demonstrate the human tendency to project our own qualities onto our deities. The traditional theological conception, he claims, is based entirely on such projections and thus fails to hit on any theological truths. The truth, according to Xenophanes, is that there is a single god, unlike human beings in form or thought, who is unmoving, but all-seeing, all-hearing, and all-thinking, and who controls the world with his mind.

          Eyes and ears are bad witnesses to people if they have barbarian souls. Fragment B107.

          In this pithy statement Heraclitus provides one of his two vivid metaphors meant to illustrate the fundamental importance of understanding the logos. Without an understanding of the logos, or the divine law or plan within nature, observation is absolutely useless. To try to investigate nature without understanding the logos, is like trying to gain meaning from words without understanding the language to which they belong: all that you perceive, in both these cases, is meaningless noise. (A barbarian is literally just a person who does not understand Greek).

          That which is there to be spoken of or thought of must be. Fragment B6

          With this idea as his guiding principle, Parmenides effected a revolution in Presocratic thought. He maintained that one could only coherently speak about or think about being, rather than non-being, and using just this premise he deduced a picture of the nature of reality that completely contradicts everything experience tells us: he argued that reality is (1) eternal, (2) unchanging, (3) just one single thing, of a single, undifferentiated, qualitative type, and (4) unmoving. All later Greek philosophers, including Plato and Aristotle, had to contend with these arguments in putting forth their own theories of the nature of the world.

          By convention sweet, by convention bitter; by convention hot, by convention cold; by convention color; but in reality: atoms and the void.

          For those Post-Parmenidean Presocratics who refused to believe that the world is nothing like we experience it, the challenge lay in giving an account of the observable world, while not contradicting Parmenides' well-argued conclusions. The above statement sums up Democritus' resulting view on the nature of ultimate reality: the only truly real objects of the world, he is here claiming, are atoms and the void. The observable world, which arises from the arrangement and rearrangement of these atoms, is less real. Since only the atoms and the void are truly real, any change, plurality, etc. that we observe in our experience, is not a true violation of Parmenides' requirements for the real.

          Overview

          All human activities aim at some end that we consider good. Most activities are a means to a higher end. The highest human good, then, is that activity that is an end in itself. That good is happiness. When we aim at happiness, we do so for its own sake, not because happiness helps us realize some other end. The goal of the Ethics is to determine how best to achieve happiness. This study is necessarily imprecise, since so much depends on particular circumstances.

          Happiness depends on living in accordance with appropriate virtues. Virtue is a disposition rather than an activity. That is, a virtuous person is naturally disposed to behave in the right ways and for the right reasons, and to feel pleasure in behaving rightly. Virtue is a mean state between the extremes of excess and deficiency. This mean varies from person to person, so there are no hard and fast rules as to how best to avoid vice.

          Only voluntary actions are praiseworthy or blameworthy. We can define voluntary action as any action that originates in the agent and not in some outside force like a push or a stumble. There are borderline cases, however, as when someone is compelled to behave dishonorably under severe threat. Voluntary action is characterized by rational deliberation and choice, where the agent determines the best course of action by reasoning how best to achieve desirable ends.

          One by one, Aristotle discusses the various moral virtues and their corresponding vices. Courage consists of confidence in the face of fear. Temperance consists of not giving in too easily to the pleasures of physical sensation. Liberality and magnificence consist of giving away varying amounts of money in appropriate and tasteful ways. Magnanimity and proper ambition consist of having the right disposition toward honor and knowing what is one’s due. Patience is the appropriate disposition toward anger, though it is sometimes appropriate to show some degree of anger. The three social virtues of amiability, sincerity, and wit make for pleasant and engaging interaction with others. Modesty is not properly a virtue, but an appropriate disposition toward shame, which is admirable in the young.

          Justice in a sense encompasses all the other virtues, since being just consists of exhibiting virtue generally. In human affairs, there are two primary forms of justice: distributive and rectificatory. Distributive justice deals with the distribution of wealth or honors among a group of people and should be given according to merit. Rectificatory justice deals with exchanges between two or more people and should always aim at restoring a sense of balance and equality between the people concerned. It is impossible to treat oneself unjustly or to suffer injustice willingly. While the laws are a good guideline, they do not cover every particular case. On occasion, agreed-upon equity must settle cases that the laws do not.

          While the moral virtues dispose us to behave in the correct manner, it is necessary also to have the right intellectual virtues in order to reason properly about how to behave. There are five intellectual virtues. Three of them—scientific knowledge, intuition, and wisdom—consist of contemplative reasoning, which is detached from human affairs. The other two—art or technical skill and prudence—consist of calculative reasoning, which helps us make our way in the world. Prudence is the intellectual virtue that helps us reason properly about ethical matters.

          Incontinence is a peculiar form of badness. Unlike vice, incontinence does not involve willing bad behavior. Rather, it consists of knowing what is good but lacking the self-control to do good. Incontinence is not as bad as vice, since it is partially involuntary.

          There are three kinds of friendship: friendship based on utility, friendship based on pleasure, and friendship based on goodness of character. The first two kinds of friendship are based on superficial qualities, so these sorts of friendship are not generally long lasting. Friendship based on goodness of character is the best kind of friendship, because these friends love one another for who they are and not for what they stand to gain from one another. Friendship generally exists between equals, though there are cases, like the father-son relationship, which rely on unequal exchanges.

          Political institutions rely on friendly feelings between citizens, so friendship and justice are closely connected. There are three forms of constitution based on different kinds of relationships. Of the three, monarchy is preferable to aristocracy or timocracy.

          Ideally, our feelings for our friends should reflect our feelings for ourselves. Self-love is more important than friendship, since only people who treat themselves with appropriate care and respect can achieve proper virtue and happiness. Though a happy person is theoretically self-sufficient, friendship is an important and essential aspect of the good life.

          Pleasure accompanies and perfects our activities. A good person will feel pleasure in doing good things. The highest good of all is rational contemplation. A life that consists exclusively of contemplation is obviously impossible, but we should aim to approximate this ideal as closely as possible. The practical sciences, then, help us find the right path toward this highest good and help us deal with the practical matters of everyday life that inevitably occupy a great deal of our time and attention.

          Key Facts

          Thales

          dates  ·  The only date regarding Thales' life that we know for certain, is the year that he predicted a solar eclipse, 585 B.C. The historian Apollodorus suggests that Thales was born in 625 B.C., but this claim should be accepted with some caution. Apollodorus tended to calculate birth dates on the assumption that a man was forty years old at the time of his greatest achievement.

          place of residence  ·  Thales lived in the city of Miletus in Ionia in Northern Greece.

          philosophical school  ·  Thales was the first of the Milesian philosophers, so called because they all resided in the city of Miletus. The Milesians, like Thales, were preoccupied with natural philosophy and with giving an account of the origins of the universe.

          philosophical interests  ·  Thales' interests were broad ranging (for instance, he was famed as a military engineer), with his philosophical interests covering everything from natural philosophy, metaphysics, mathematics, and astronomy.

          available evidence for his thought  ·  We have no direct quotations (fragments) from any work of Thales. In fact, it is not even clear that he wrote down any of his theories. Our only information regarding his philosophy comes from five separate reports (testimonia) in Aristotle, all of which seem to themselves come only from second-hand reports, not from any first-hand familiarity with Thales' work.

          Anaximander

          dates  ·  Anaximander was born in roughly 600 BC and lived until roughly 550.

          place of residence  ·  Like Thales, Anaximander lived in Miletus, in Ionia, Greece.

          philosophical school  ·  Anaximander was the second of the three Milesians.

          philosophical pedigree  ·  Anaximander was almost certainly a student of Thales, and the teacher of Anaximines

          primary philosophical interests  ·  Like his teacher, Thales, Anaximander's philosophical interests seem to have ranged over the subjects of natural philosophy, metaphysics, astronomy, and mathematics.

          available evidence for his thought  ·  As with Thales, there are no direct quotations available from Anaximander's work, though we do know that he wrote books. The testimonia we have in the case of Anaximander are more numerous in number, however, than in Thales' case, and they also derive from a wider array of sources, including Aetius, Simplicius, and Pseudo-Plutarch in addition to Aristotle.

          Anaximines

          dates  ·  There are no known dates concerning Anaximines, though we do know that he was slightly younger than Anaximander.

          place of residence  ·  Anaximines was also from Miletus, in Ionia Greece

          philosophical school  ·  Anaximines was the last of the Milesians

          philosophical pedigree  ·  Anaximines was probably a student of Anaxagoras.

          primary philosophical interests  ·  As far as we know, Anaximines only concerned himself with natural philosophy and metaphysics.

          available evidence for his thought  ·  With Anaximines, finally, we have some very short fragments in addition to testimonia.

          Xenophanes

          dates  ·  Xenophanes was born in 570 B.C.

          place of residence  ·  Xenophanes lived in Colophon, Greece, not far from Miletus.

          philosophical school  ·  Xenophanes was not associated with any known philosophical school.

          philosophical pedigree  ·  There is speculation that Xenophanes was the teacher of Parmenides at one time.

          philosophical interests  ·  Xenophanes did seem to engage in some natural philosophy and metaphysics, but his primary contributions are in the fields of theology and epistemology

          available evidence for his thought  ·  We have quite a large number of very short fragments from the works of Xenophanes.

          Heraclitus

          dates  ·  Heraclitus was born in 540 B.C.

          place of residence  ·  Heraclitus lived in Ephesus, near Colophon.

          philosophical school  ·  Like Xenophanes, Heraclitus is not associated with any known philosophical school.

          philosophical pedigree  ·  As far as we know Heraclitus was neither the student nor the teacher of any other of the Presocratic philosophers. He did, however, forge his ties to history by rudely insulting all previous thinkers.

          philosophical interests  ·  Heraclitus's thought has important implications in the fields of epistemology, natural philosophy, and metaphysics.

          available evidence for his thought  ·  The evidence explodes at this stage. We have 115 reliable, but short, fragments for Heraclitus's thought.

          Parmenides

          dates  ·  Parmenides was born in 515 B.C. He published his revoltionary philosophical poem, On Nature, sometime between 470 and 460 B.C.

          place of residence  ·  Parmenides was born in Elea, in southern Italy

          philosophical school  ·  Parmenides was the founder of the Eleatic school, a movement intent on proving that reality is unchanging, eternal, and admits of no plurality.

          philosophical pedigree  ·  Parmenides may have been the student of Xenophanes. Parmenides' most famous student, in turn, was Zeno, whose brilliant paradoxes baffled the Eleatic's opponents and continue to baffle modern thinkers.

          philosophical interests  ·  Parmenides' thought had radical implications in the fields of epistemology and metaphysics.

          available evidence for his thought  ·  We have some significant (both in content and in length) pieces of his poem On Nature. These pieces were preserved in various sources, such as the writings of Sextus Empiricus, Proclus, Simplicius, Plato, Plutarch, Galen, and Clement.

          Empedocles

          dates  ·  Empedocles was born 492 B.C. and died sometime around 424 B.C.

          place of residence  ·  Empedocles lived in Acragas, Sicily

          philosophical school  ·  Empedocles was the first of the pluralists, a school intent on maintaining, in the face of the Eleatic challenges, that the world exists roughly in the form in which we perceive it.

          philosophical pedigree  ·  Empedocles was clearly heavily influenced by Parmenides, though whether he ever studied with members of the Eleatic school is unclear.

          primary philosophical interests  ·  Empedocles was primarily interested in natural philosophy, metaphysics, and medicine. Like all post-Parmenidean thinkers, he also had an interest in epistemology.

          available evidence for his thought  ·  Large pieces of his important philosophical poem have been preserved.

          Anaxagoras

          dates  ·  Anaxagoras was born in 500 B.C. In either 450 or 430 B.C., he was tried by Atheinian state for the crime of impiety and subsequently exiled to northern Ionia where he died soon thereafter.

          place of residence  ·  Anaxagoras was born in Clazomenae in Ionia, but he spent most of life in Athens, before being exiled back to Ionia.

          philosophical school  ·  Anaxagoras was a pluralist.

          philosophical pedigree  ·  Like Empedocles, Anaxagoas was strongly influenced by Parmenides, but there is no evidence that he studied with him.

          primary philosophical interests  ·  Anaxagoras's theories made important contributions in the fields of natural philosophy and metaphysics.

          available evidence for his thought  ·  For Anaxagoras, we have a few large fragments and a few telling testimonia.

          Leucippus

          dates  ·  Leucippus' dates are unknown.

          place of residence  ·  Leucippus's birthplace has been given variously as Abdera, Miletus, and Elea.

          philosophical school  ·  Leucippus was the founder of atomism, which can be viewed as a sub-movement within the larger movement of pluralism.

          philosophical pedigree  ·  Leucippus was probably a student of Zeno and was undoubtedly the teacher of Democritus.

          philosophical interests  ·  Leucippus' brand of atomism could not have failed to touch upon natural philosophy and metaphysics. Whether he had other interests besides is unknown, since none of his work remains.

          available evidence for his thought  ·  There is single fragment, one sentence long, testifying to Leucippus' thought.

          Democritus

          dates  ·  Democritus was born in 460 B.C. and died in 375 B.C.

          place of residence  ·  Democritus was born in Abdera, Thrace in Northern Greece, but he traveled extensively throughout the ancient world.

          philosophical school  ·  Democritus was the philosopher responsible for bringing atomism to public attention.

          philosophical pedigree  ·  Democritus was the student of Leucippus.

          primary philosophical interests  ·  Demorcitus believed that atomism could be usefully applied to all fields of inquiry. He wrote treatises covering natural philosophy, epistemology, metaphysics, ethics, politics, and mathematics, among other subjects.

          available evidence for his thought  ·  Most of our evidence regarding the thought of Democritus comes from in depth testimonia, but there are also some shorter fragments in existence.

            

          Important Terms

          Aer  -  Aer was the physis according to Anaximines. He apparently conceived of air as a thick mist.

          Apeiron  -  "Apeiron" is the Greek term for Anaximander's Unbounded. The Unbounded was Anaximander's physis. It was an infinite, eternal, and indefinite substance, without any properties of its own.

          Arche  -  Arche is the Greek term for "first principle." Aristotle often referred to each Presocratic's physis as an "arche," but this terminology, because of the high level of sophistication it involves, is misleading when applied to the Presocratics.

          Eleatics  -  The Eleatic philosophers were the followers of Parmenides of Elea. Zeno and Milessus are the two most famous Eleatics. The school of Elea was the first western school of thought to consider pure, abstract reason (as opposed to observation)as the sole criterion of truth. The theory they propounded, arrived at only through the use of pure reason, contradicted everything about our experience of the world.

          Epistemology  -  Epistemology is the branch of philosophy concerned with human knowledge.

          Empiricism  -  Empiricism is the theory that all knowledge arrives in the mind through sensory experience.

          Homeomeric Substances  -  Homeomeric substances are the most basic, most real components of the world according to Anaxagoras. They are substances without differentiated parts. So, for instance, bone or flesh would be a homeomeric substance, but a chair would not be.

          Logos  -  According to Heraclitus there is a logos, or divine pattern, that guides and unifies all of nature. It is only by understanding the logos that we can make sense of our experiences and arrive at knowledge about the nature of the world.

          Material Monism  -  Material monism is the position that all objects in the world are variations on a single substance. All of the Milesian philosophers were probably material monists, though they differed about what substance comprised the building block of nature.

          Metaphysics  -  The branch of philosophy concerned with asking what there is in the world. Questions about physis are metaphysical questions, as are questions about the gods.

          Microcosm/macrocosm principle  -  A principle of reasoning drawn on heavily by early Greek thinkers. The microcosm/macrocosm principle uses observations about the human organism (or some other organism, or even human society) and draws inferences about the entire universe from these observations.

          Milesians  -  Thales, Anaxagoras, and Anaximines were the three Milesians. They are grouped together primarily because they were all from Miletus in Ionia and also because they are linked by student-teacher relations. They also, however, have strong similarities in their world systems, including a preoccupation with natural philosophy and a tendency toward material monism.

          Natural Philosophy  -  Natural philosophy is the branch of philosophy that covers all questions we would now call "scientific." It is concerned with observing natural phenomena and providing explanations to explain their occurrence. The attempt to give a cosmogony is an example of natural science, as is the attempt to give theories of origins of human life.

          Nous  -  "Nous" is the Greek term for "mind." According to Anaxagoras, nous is the rational force within nature, guiding and ordering the cosmos.

          The Parmenidean Real  -  Parmenides threw all of philosophy into a crisis when he argued rigorously that the only possible reality was one that does not correlate at all with our sensory experience. All that exists, he claimed, is a single, continuous, spherical, eternal, unchanging, unmoving thing with no qualities or characteristics.

          Phusikoi  -  Aristotle referred to the Presocratic philosophers as "phusikoi," because of their preoccupation with identifying the physis of nature. We derive our modern term "physicist" from this word.

          Physis  -  There are two senses in which something can be a physis. A physis can either be the substance out of which everything else in the world arose, or else it can be a unifier within nature. In other words, a physis is either a substance that is the most basic constituent of the world—of which everything else is somehow a variation, or else it is some pattern through which all things in the world form a unity. The Presocratics were particularly keen on identifying the physis of the world. See also apeiron, aer, logos.

          Pluralists  -  The pluralists believed that there were multiple physis in the world. They were all reacting against the Eleatics, and so they claimed that each of their physis was, in fact, the Parmenidean Real.

          Principle of Sufficient Reason  -  The principle of sufficient reason asserts that there is no effect without a cause or no change without a reason for change. The principle is most closely linked to the philosopher G.W. Leibniz, who first gave it its explicit formulation as well as its name. It was first used, however, by Anaxagoras of Miletus, in arguing that the earth needs no material support.

          Pythagoreans  -  Followers of the philosopher, mathematician, and religious cult leader Pythagoras. Pythagoreans made important advances in geometry (such as the discovery of the Pythagorean theorem) and also believed in the transmigration of souls. Their ideas had an influence on several of the Presocratic philosophers.