5. PHILOSOPHY AS TELEOLOGICAL SCIENCE In the previous lecture we looked at the ideas of Socrates and his follower, Plato. Socrates' universal appeal to reason and Plato's use of dialogue to construct a system based on Socrates' teachings revolutionized the development of philosophy in ancient Greece. At the end I mentioned Plato's notion that idealism can lead to the construction of a universal science. The fact that virtually no scientists today would look back to Plato's ideas as the source of modern science suggests the extent to which Plato failed in this task (at least, given modern notions of what "science" is). However, as we shall see today, the system proposed by Plato's most influential pupil was to succeed in this goal in a way his teacher's ideas never would. Having studied at the famous school Plato had founded, called the "Academy", Aristotle taught there until after Plato's death. During those twenty years he obviously would have become thoroughly familiar with Plato's ideas. He then left the Academy, however, and served for about three years as the private tutor for Alexander the Great. Upon his return to Athens, he set up his own school, where he developed and taught a system of philosophy which many regard as being diametrically opposed to Plato's. Unfortunately, all that survives of Aristotle's writings are his lecture notes and textbooks intended for use by his students. As a result much of his writing is dry, and considerably less entertaining than Plato's lively Dialogues. Indeed, whereas Plato's writing style sometimes obscures his meaning by being too loose, Aristotle's meaning is often obscured by his rigidity. Something in between would, no doubt, make for a more suitable style for presenting philosophical insights. Aristotle based his system on a metaphysics which virtually stands Plato's idealism on its head. Aristotle argued that particulars, not universals, are ultimately real. He connected particulars with a special term, "ousia", which itself means "reality", though it is usually translated as "substance". The basic question in his "first philosophy" (as he referred to metaphysics) is therefore "What is substance?" He answered this question by defining a substance as an individual, existing thing (see Categories, pp.1b-4b). Such a "thing" is not merely a form, nor is it a hunk of matter. Instead, it must always combine matter and form within itself. Substance combines form and matter in such a way that the matter fulfills a necessary function, rather than being just an accident or an illusion. For the material of a substance gives it its "distinctive mark", which is that, "while remaining numerically one and the same, it is capable of admitting contrary qualities" through a material change. For example, the chalk I am now holding in my hand would still be an example of the substance "chalk" even if it changed from having the quality of white chalk into having the quality of red chalk. This way of looking at the nature of reality is typically called "realism". Aristotle further developed his realism by distinguishing between "primary" and "secondary" substances. Whereas "primary substances ... are the entities which underlie everything else", secondary substances are the characteristics which can be "predicated" of that individual thing, especially if they are part of the definition of what it is (p.2a-b). Strictly speaking, the latter should be limited to the "genus" and "species" to which the individual thing belongs. For instance, I as an individual human being am a primary substance. The fact that I am a man (species) and an animal (genus) are therefore secondary substances, describing what kind of substance I am. In a looser sense, however, anything which is "either predicated of [primary substances] or present in them" can be regarded as a secondary substance. Thus, primary substances usually appear in the subject of sentences, whereas secondary substances usually appear in the predicate. Aristotle developed his theory of substance at the beginning of his book Categories, where "category" is defined as a "most general kind of thing". The word "form" can itself be regarded as meaning "of such a kind", so a category is a very generalized form. In Categories Aristotle collected a list of the ten most general kinds of form, the first of which is substance itself (i.e., the kind of form which is made real by participating in matter). The other nine are characteristics that help us to understand what a particular substance is like. There is no need for us to go into detail here about the nature and function of these categories. It will be enough simply to mention that the other nine are, in the order Aristotle presented them, quantity, quality, relation, place, time, position, state, action, and affection (p.1b). Much of Aristotle's discussion of these categories concerned the way we use such terms in language (thus foreshadowing today's emphasis on linguistic analysis, to be discussed further in Lecture 13). But he also clearly regarded them as providing an orderly and systematic way of understanding reality itself (i.e., substances). In applying his realism to particular cases Aristotle used a teleological method. That is, he argued that a thing's form can best be discovered by inquiring about its purpose. The Greek word telos ("purpose") also refers to the end or goal of a thing or an event. Why does it exist? What is it used for? Such questions will help us to explain why a particular piece of matter has the particular form it does. Aristotle used his teleological method as an integral part of his task of classifying numerous natural and intellectual objects. For his philosophical method had a dual emphasis on logical (linguistic) classification and teleological (empirical) observation. This dual emphasis has had a lasting influence on all those who have since followed what we could refer to as the "empiricist" tradition. Modern science is, of course, one of the fruits of the empiricist tradition. So it should come as no surprise to find that many of the names we now give to the different branches of the sciences, as well as other academic disciples, were first established as such by Aristotle's teleological classifications. Many of his books were devoted to naming and providing a basic grounding for disciplines such as "psychology", "zoology", and even "metaphysics" itself. Thus, for instance, he distinguished between mathematics, physics, and theology, by saying they deal with formal, material, and divine causes, respectively (Metaphysics, p.1026a). Moreover, he established many distinctions we now take for granted, not only in philosophy (such as essence-existence and cause-effect), but also in empirical science (such as genus-species and plant-animal-human). This certainly justifies the tradition that regards Aristotle as a kind of "grandfather" of modern science, even though his own teleological methodology is now discredited by most scientists. (Most, but not all. The Anthropic Cosmological Principle is a significant example of a recent book in which scientists do recognize the value of the teleological method.) Let me explain the epistemological difference between Aristotle's realism and Plato's idealism by using this piece of chalk as an example. How do we know this piece of chalk is a piece of chalk? What makes it what it is? Plato would say the idea of chalk, or "chalkness", gives this object its reality. That means, even if we were to go on a crusade all around the world destroying each particular piece of chalk that now exists, we would not in so doing change the reality of "chalkness" in the least. Even if we systematically erased all written references to chalk in all the world's literature, and waited for the death of every person who had ever seen or used chalk, its idea would still be just as real as it is today: it would still be an eternally existing form, waiting to be remembered by some future generation. This piece of matter we call chalk is real only because it participates in a real idea, the idea of chalkness. Aristotle, by contrast, would say the reality of this particular substance I am holding in my hand, which we call "chalk", is dependent not only on its participation in the form of "chalkness", but also on the ability of some collection of matter to instantiate (i.e., serve as a real example of) that form in the world we experience. This means the matter must be able to fulfill the purpose of chalk. What purpose does "chalkness" bestow on a lump of matter? What is chalk used for? Obviously, when it appears in a classroom, at least, chalk is used to write things on the blackboard. So if I drop this piece of chalk on the ground and then crush it--like that (don't tell the cleaners I did that!)--then Aristotle would say I have destroyed the substance, the reality of the chalk. In this case the matter is still there, but its form no longer exists as chalk. For both Plato and Aristotle, then, a thing's form is a necessary factor in determining its reality. But for Plato the form alone is sufficient, while for Aristotle a definite link with matter is also required. Their views can be summarized quite simply in the following way: Plato's Idealism Aristotle's Realism Form = reality Form + Matter = Matter = illusion substance (reality) This summary, of course, only scratches the surface of Aristotle's account of the nature of substance, but it will suffice for the purposes of this brief introduction. What about Aristotle's view of human nature? How did his new metaphysical standpoint, his realism, influence the way he understood the reality of being human? He agreed with Plato that the soul (psyche) is the form of the body. As such, its main functions are described in terms of "the nutritive, the appetitive, the sensory, the locomotive [powers], and the power of thinking" (De Anima, p.414a). But the body itself is now regarded as not just an accident, or an illusion to be overcome, but as a necessary constituent of the human substance, through which these powers are realized. I would guess that this view feels far more natural to most of us than Plato's idealist view; yet some of its consequences may be less than desirable. For if the body is a necessary element in being human, then when the body dies, so does the reality of the individual existing person. A soul alone would have no more reality than the mere idea of "chalkness", and would be of no more use than the pile of chalk dust here on the floor is for writing on the chalkboard. And this negative implication of Aristotle's realism, for anyone who believes in life after death, begins to make Plato's idealism look not so bad after all! (Another way around this problem would be to believe the body itself is somehow brought back to life, albeit in some transformed state, after we die. We will discuss this possibility further in Lecture 27.) Aristotle himself tried to make up for this negative consequence of his realism by pointing out that the human soul does have one distinctive purpose, which makes mankind different from all other earthly substances. That purpose is rationality (nous), which some scholars have interpreted as a "spark of the divine" in man. Accordingly, he referred to man as the "rational animal", a notion which has become one of the most widely accepted ways of defining human nature. And in De Anima (p.430a) he stated that, when the soul "is set free from its present conditions" (i.e., when a person's body dies), the remaining core of rationality "is immortal and eternal". This does seem to imply that the "spark" of rationality in an individual's soul will eventually return to the "fire" of God from which it came. In any case, there is still no survival of the individual; yet there is a universal goal to keep us going and to make life worth living. If the purpose of life is to expand and develop rationality to its maximum extent, then obviously philosophy is the most meaningful vocation a person can pursue. For in Aristotle's view, the philosophical part of you, and that part alone, will survive your death. There are many other aspects of Aristotle's philosophy which would be interesting for us to discuss here if we had more time. I'll conclude by just mentioning his idea that all movement in the world originates in a "Prime Mover" which is itself "unmoved". This Being is itself the "final cause" (i.e., the ultimate purpose) of all movement. In other words, all changes in the world around us are driving towards a final point of rest, in which they will return to their source in the unmoved Mover. And this, of course, is regarded by many modern readers as an interesting account of the Being we normally call God. QUESTIONS FOR FURTHER THOUGHT 1. Is matter an illusion? 2. What is purpose? 3. Does irrationality have a purpose? 4. What will it be like after I die? RECOMMENDED READINGS 1. Aristotle, Categoriae ("Categories"), tr. E.M. Edghill in Richard McKeon (ed.), The Basic Works of Aristotle (New York: Random House, 1941), pp.7-37. (The page numbers cited in the above lecture refer to the pagination of the Greek text, given in the margins of the translation.) 2. Aristotle, De Anima ("On the Soul"), tr. J.A. Smith in ibid., pp.533-603, especially Book III, pp.581-603. 3. Aristotle, Metaphysica ("Metaphysics"), tr. W.D. Ross in ibid., pp.681-926, especially Book V, pp.752-777. 4. John D. Barrow and Frank J. Tipler, The Anthropic Cosmological Principle (Oxford: Clarendon Press, 1986), especially Chapter Two, "Design Arguments", pp.27-122.