Definition of Philosophy (Phillips)
From The Logic Museum
From Modern Thomistic Philosophy, R.P. Phillips, London 1934
THE DEFINITION OF PHILOSOPHY
To be Looked for in Philosophy as an Existing Fact—In Its History—Thales and the Ionic School—The Pythagoreans— The Eleatics—Heracleitus—The Atomists—Anaxagoras—Socrates and Plato—Aristotle—Conclusion.
MOST people have the vaguest ideas, if any, of what philosophy is, or of what the word philosophy means. It is commonly used only in such expressions as: 'he took the affair philosophically,' in which, no doubt, it is implied that philosophy helps a man to bear up against misfortune, and that philosophers are calm and unexcitable people; though why they should be so does not appear. Consequently, we are not much nearer any knowledge of what philosophy is in itself. It is, however, essential for the student to have, at the start, some notion of the nature of the subject which he is about to study; though it is evident that it can only be a rough and provisional one. He will have to determine for himself at the end of his study (if that ever comes) whether it is finally satisfactory. The definitions which the text-books of Scholastic philosophy put on their opening pages are often hurled at the reader's head without much proof that they are correct, so that they have to be taken on faith, on the authority of the author. They thus fail to  satisfy the mind or arouse the interest. It seems desirable, therefore, that a man should be led to discover for himself what philosophy is in fact. Now, everyone will agree, that if we want to discover the nature of a thing the right way to do so is to examine it. To do this in the case of philosophy, we must see what subjects are discussed by it, i.e., examine it in the course of its history. It will not, however, be necessary to review its entire history, but it will be sufficient if we see what its character was during the period of its formation, which is that of the Greek philosophers till the time of Aristotle.
Though it may well be that further precision might be imported into our definition by continuing our enquiry down to the present day, nevertheless, if it be granted that the thought of Aristotle and his predecessors is philosophy in process of formation, we shall, by examining it, be able to discover what the essential character of philosophy is. Just as the child is the father of the man, and retains the same nature throughout his life, so Greek philosophy is the father of modern, and thus in its nature the same. By following this a posteriori method we shall avoid the danger of making philosophy out to be what we think it ought to be; and at the same time the glimpse which will thus be caught of the beginnings of philosophy will be a help and a guide in the subsequent study of it.
The reason of our choice of Greek philosophy for our enquiry is, that it was in Greece that philosophy first appeared as an autonomous science, distinct from religion, so that it can be examined there in a more or less pure state.
According to Aristotle, whose opinion on this point is generally accepted, Greek philosophy begins with Thales of Miletus (c. 624-550 B.C.). He and his immediate successors were engaged on the problem of discovering the nature of the visible world; and this is natural, for as soon as a man begins to think, that which first attracts his attention is the world as presented to him in sensation, as being the most obvious aspect of it. The opinions of Thales, as far  as we know them from tradition, since he left no writings, are summarised in two propositions: first, that water is the principle of all things; and secondly, that the earth is a flat disc floating on water. Strange and crude as these statements sound, they have a considerable importance for our purpose, since they show that what Thales tried to do was to explain the material constitution of the universe by the aid of reason alone, without appealing to religious myths, or the intervention of the gods ; whose action was then normally invoked to account for anything whose origin was obscure. He and his successors were seeking what was later called the material cause of the universe. All the pre-Socratic philosophers followed the line suggested by Thales, viz., that under the multiplicity of phenomena, of the world as perceived by sense, there must be some one permanent principle. Just as Thales asserted that this principle is water, so his successors advanced other theories as to its nature. For Anaximander it is indefinite matter, for Anaximenes air, for the Pythagoreans number, for the Eleatics being, for Heracleitus fire, for Empedocles the four elements, and for Democritus atoms.
The Ionic School
Thales was the founder of what is known as the Ionic School, from the fact that its three principal representatives, Thales himself, Anaximander and Anaximenes, were all men of Ionia. They have been called materialists, though they were not so in the modern sense of denying the existence of anything but matter : they were simply concerned to discover what the material world was made of. Just as a child might pull a toy to pieces to find out what it is made of, so these philosophers tried to pull the world to pieces with their wits, and having discovered the answer, as they thought, asked no further questions about it.
The next attempt to discover the primary constituent of' the material word which calls for notice is that made by the Pythagoreans.
 Pythagoras was born at Samos at some time between 580 and 570 B.C.; and in middle age settled at Crotona in Italy, where he founded the Pythagorean Society, which was primarily a religious and moral order, not a philosophic school. It was closely connected with the Orphic Sect, from which it took the doctrine of Metempsychosis, which would be better named Metasomatosis, since it is the theory that souls pass from one body to another. The philosophy of the Pythagoreans is the philosophy of number, for they held that number is the stuff of which the world is made. They were probably inclined to this strange opinion by their mathematical researches, for which Pythagoras himself was remarkable. It is thought that the first book of Euclid is substantially attributable to him, and he is said to have sacrificed an ox in honour of his discovery of the 47th proposition. Observing the world about them the Pythagoreans remarked that we recognise objects by means of their qualities. The various classes of things have, however, different qualities, and it seems at first sight that there is none which is common to all. Further examination shows us, nevertheless, that there is one characteristic which is possessed by everything, that of quantity or number. All things are numerable, and can be counted. We are reminded of the saying of Galileo: ' Philosophy is written in the great book which ever lies before our eyes—I mean the universe —but we cannot understand it if we do not first learn the language in which it is written. This book is written in the mathematical language' ; though the ideas of the Pythagoreans were much more primitive, and enveloped in an atmosphere of mysticism. They concluded, indeed, from the universal character of number and from the order and harmony of the universe, not merely that number is a most important element in it, but that it is its very essence, that the universe is made of number, just as Thales had said it is made of water. Number is the ultimate, the only reality. Further, from the opposition of the determined and the indeterminate or infinite, are derived all the fundamental  contrarieties : equal and unequal, one and multiple, left and right, male and female, rest and movement, light and darkness, good and evil. These dominate the nature and activity of things, so that every essence has its number, and every essence is a number. This doctrine, fantastic as it is—though it has marked affinities with the way in which the universe is regarded by modern mathematical physics—is nevertheless some advance on the teaching of the Ionians, since it declares that the ultimate material of the universe is something more abstract and so more universal than was allowed by them. It belongs, however, to the same type of enquiry as that of the Ionic School—the enquiry, namely, as to the stuff of which the material universe is, in the last resort, constructed. Consequently, it is on sense knowledge that all these thinkers rely, for it is by the senses that we are made acquainted with material things; so that the first stage in philosophy is similar to the first stage in the development of the individual mind, when the child is filled with curiosity as to the things around him, trying to find out what they are made of by sucking them, sticking his fingers in them, and pulling them to pieces ; but hardly asking the reason of them or using his intellect about them. This will be the next stage in his mental life, and so it was also in the growth of philosophy; for the group of thinkers who now claim our attention try to investigate the reason of things, and not merely the stuff of which they are made. They ask not merely what things are made of, but why they are as they are. In this way they are of importance for our present purpose since they add a new feature to the conception of philosophy.
These philosophers are known as the Eleatics, since their school was situated at Elea in Southern Italy. The founder of this famous school is said to have been Xenophanes, a kind of troubadour, but its chief representative is Parmenides, who was born about 514 B.C. His reflections take their rise from the observation of the changing character of things. Since everything about us is constantly changing, it seemed to him that no knowledge of it was possible. Just as in  sense knowledge, it is impossible, when looking at a rapidly revolving wheel, to have knowledge of the spokes, since they have passed on before they can be seen, so knowledge in general demands that its object should be momentarily, at least, at rest, in order that it may be seized. If, then, there is to be knowledge at all, there must be some unchanging reality underlying this shifting surface of the world. This reality cannot be known by the senses which tell us only of this superficial aspect of the world. If it is to be known at all then, it must be by the intellect, which penetrates beneath the surface, and what this sees everywhere in things is that they are, is their being. This, then, must be the reality of things, and all that is not being is unreal. Being is (i.e. is reality)—not-being is not: the. first formulation of the principle of identity, the supreme law of thought. As he considered further this underlying reality of pure being, which is wholly unmixed with not-being or becoming, Parmenides saw that it must be perfectly one and completely immutable : it has no beginning or becoming ; for if it has, it must come either from being or not-being. If from being, it does not come to be, since it already is : and from not-being or nothing, nothing comes. To maintain this position, however, he was forced to deny the testimony of the senses, which show us being in a state of change, of becoming, and he does not scruple to do so. He thus makes a distinction which is henceforth to be of fundamental importance for philosophy, the distinction between sense and reason. True being is known to us only by the reason, the senses present to us a world which is false, which is appearance only, and an illusion. By a curious inconsistency, however, which was apparently unnoticed by himself, Parmenides conceived of this one Being as material, as occupying space, finite and spherical. That this is an inconsistency is clear, for Being is a purely abstract intellectual concept, and cannot have any material characteristics: for it would thus be amenable to sense knowledge and so be not-being, and like all else that is sensed, an illusion. Nevertheless, this inconsistency in his doctrine was the reason why, in fact, there issued from it the two opposing schools of intellectualism and materialism.  Since Being neither arises nor passes away, if we adhere closely to his doctrine that Reality is to be known only by the reason, and not by the senses, we shall conclude that there is only one Being which has no material or sensible qualities, but is eternally the same—an absolute Monism of a type which has become familiar in modern philosophy. If, on the other hand, we accept his statement that Being is material, we are led to the doctrine of the absolute indestructibility of matter; matter has no beginning and no end, which is materialism. The first aspect of his doctrine represents, however, his most striking and original contribution to philosophy, and therefore we rightly see in him the founder of Intellectualism and Idealism.
The most outstanding of the disciples of Parmenides was Zeno (born about 489 B.C.), who, in support of the theory that Being is immutable, developed some famous arguments to show that motion is impossible, and that the very idea of it implies contradiction. The best known of these arguments, which are dealt with in Cosmology, is that of Achilles and the tortoise. Achilles and the tortoise run a race, and if the tortoise is given a start, Achilles can never catch it up. For, first, Achilles has to run to the point from which the tortoise started. When he arrives there, the tortoise will have moved to a further point; and when Achilles reaches this, the tortoise will have gone on still further. This process will be indefinitely repeated, in such a way that the distance between the two will be always diminishing, but never wiped out; so that Achilles will never catch up the tortoise. This and similar arguments are meant to show that essential contradictions are involved in our ideas of space and time.
The antithesis of this static philosophy of the Eleatics is found, at about the same time, in the dynamic philosophy of Heracleitus (c. 535~475 B.C.). He was an aristocrat of Ephesus, a sardonic man, who despised not only the common run of men, but even men of great reputation, such as Homer  and Hesiod. As Parmenides had done, he sees that all the world around us is perpetually changing; but instead of rejecting this appearance of change as illusory, and asserting that the reality must be other, he accepts it, as itself the basic reality. For him there is no stability in the universe, but all is change. His view is summed up in the laconic phrase vdvra fa. Beneath this flux there is no principle which is stable and permanent, so that we must not shrink from affirming that the thing which is, the changing thing, at the same time is not, since there is nothing which remains even for a moment beneath the change. This movement, this Becoming, which is pictured by Heracleitus under the form of Fire, is all there is, and all differentiations of things merge into it. Thus, no less than Parmenides, Heracleitus, the originator of the philosophy of change, is led to a pure monism; the assertion that all reality is one and undifferentiated.
This fact suggests two important points with regard to the nature of philosophy :
1. The human mind tends to reduce all things to a simple unity; and that this must be so, we shall see, is accounted for by S. Thomas' theory of its working. Hence philosophy is the business of accounting for the many by the one, of bringing particular cases under general laws, and in the last resort of accounting for all things by one principle, cause and ground. This effort, pushed to an extreme, ends in Pantheism or Monism, and it is so pressed in the two philosophies we have just been considering. Extremes meet.
2. But though they are extremes, yet they are antithetically opposed, since one denies all motion, the other all rest; and between these, philosophy has oscillated ever since. Both owe their attraction to what is, in fact, their weakness, viz. the denial of one of the elements in the problem. They are attractive, being clear cut: weak, being inadequate.
This suggests a further point, viz. that the truth is likely to be found in neither of these, but in a synthesis which combines them, and, in fact, the main trend of philosophy has been in the direction of such a synthesis, the broad lines of which were marked out by Plato and Aristotle.
 A synthesis of this kind was indeed attempted, almost at once, by Empedocles (c. 495-435 B.C.), who seized on Parmenides' principle of the unchangeable character of Being, and, interpreting it in a materialistic sense, asserted that matter is indestructible and eternal. On the other hand, he admitted the truth of the assertion of Heracleitus that change is a reality ; in which case, the change of matter must be, not an absolute coming into being of it, which would be contrary to the Eleatic principle, but a simple mixing and unmixing of it, to form various bodies. There are, according to him, four fundamental kinds of matter which, unchanged in themselves, combine to form the various kinds of bodies. These are earth, air, fire and water, which were later known as the four elements. This theory marks a transition from the more or less idealistic doctrines of the Eleatics and Heracleitus to a fully developed mechanical and materialistic philosophy, elaborated by Democritus and the Atomists.
According to Democritus (c. 470-361 B.C.), if we could divide matter far enough, we should ultimately come to indivisible particles which, though extended, are too small to be perceptible by the senses; these he called atoms Now, since they fill space and have no interstices they constitute the Plenum, and correspond to the ' Being' of Parmenides. Side by side with the atoms, which have no qualities except to fill space, Democritus acknowledges another reality, the Vacuum, which is also extended. That he must allow the reality of this is clear, since he admits the reality of change, which is nothing but the motion of the unchangeable atoms in space. Hence space must exist and be real, and indeed it has all the reality of atoms, which is nothing else than extension. This Vacuum corresponds to the • Not-Being ' of Parmenides. Thus, according to Democritus, both Being and Not-Being are real, and are extension. All the motion in the world is determined by the nature of the atoms, which is their size, or weight, since there are no holes in them. Hence the bigger atoms fall faster from the  necessity of their nature: and thus, Democritus is led explicitly to rule out any idea of freedom, or directing intention in the constitution of the world, or its development. All comes about by a blind mechanical motion. It originates by chance, and it develops by the necessary law of its nature. In these theories the question as to the origin of the world is, at least obliquely, answered. How did it come to be ? It did not, since matter is eternal and indestructible; and the force which moves it is simply natural to it.
This answer, however, did not satisfy Anaxagoras (c. 500- 428 B.C.) ; for he saw that blind forces and mechanical motion could not produce such an ordered and harmonious universe as that which we see. Nature, moreover, shows design: all, or many, of its operations being directed to the production of ends. Such order and purpose, he thought, could only be produced by an agent which is rational, non- physical and incorporeal—an intelligence or Nous. Aristotle praises him for this entirely original contribution to philosophy : ' he seemed like a sober man in contrast with the random talk of his predecessors.'
He is thus the first to show that philosophy must include, beside the discussion as to the composition and genesis of bodies materially speaking, an investigation as to the ultimate final and efficient causes of the universe ; and moreover the first to make clear the distinction between mind and matter, and between blind mechanical chance and purpose.
Thus closes the first period of philosophic thought in which philosophy has chiefly concerned itself with the attempt to discover the composition of the material world; and the discussion of its most obvious elements, matter and motion. Thus philosophy, in its infancy, took stock of the world of sense about it, and hardly gave a thought to itself, to man who observes this world, and the mind by whose means he does so. The consideration of these things was  now to be the main business of Greek philosophy, and the link between the new and old is to be found in the introduction of the all-ordering Intelligence postulated by Anaxagorus.
Philosophy did not, however, pass at a bound from childhood to mature manhood; it had first to pass through a period of stagnation and even of decadence—to sow its wild oats.
This is the period of the Sophists, for whom philosophy was a mere means of getting on in the world. It became therefore their slave instead of their mistress, and they did not aim at discovering truth, but only at finding arguments which would flatten out any opponent. This led naturally enough to Scepticism—or doubt as to the possibility of arriving at any knowledge—and Subjectivism—the contention that that is true which appears so to me, or to any individual. Among the Sophists perhaps the most famous are Protagoras and Gorgias. The propositions which the latter undertook to prove : (i) that nothing exists, (2) that if anything exists, it cannot be known and (3) that if it can be known, the knowledge of it cannot be communicated, were typical of Scepticism ; and the dictum of Protagoras, ' man is the measure of all things ; of what is, that it is; of what is not, that it is not;' of Subjectivism. These two, Scepticism and Subjectivism, are twin diseases to which philosophy ever since has been subject.
A new era of health and vigour opens with the teaching of Socrates after this short period of decadence; for the Greek mind was still young and strong, and could not long succumb to the enervating cynicism of the Sophists. The spokesman of the revolt was an artisan, a rough and ugly fellow, who loved to argue at the street corners and let the wind of common sense sweep away the pretensions and high-flown arguments of the Sophists. This Socrates, unlike the earlier philosophers, was not so much concerned with the nature,  origin and working of the material world, as with man himself. He regarded philosophy as the means which a man should use in order to lead the life which will satisfy his highest aspirations—it was to serve as the guide of life, just as Christianity, in so far as it lays down a moral law, is intended to do for us. His interest in it, therefore, was much more poignant and personal than that of the somewhat academic speculations which we have just reviewed. Now, in order that we may lead the ' good life,' we must know what good is .' and Socrates maintained that all knowledge is knowledge through concepts. Concepts, moreover, are the notions we have, not of particular things, but of the essences or natures of things; and these concepts we express in definitions which are absolutely fixed and unchangeable. Hence the Sophistic notion that the truth will vary according to the mind of the individual is altogether repugnant to Socrates; and he insists that it is to be judged by an absolute standard, not by any subjective impressions. Just as in measures the State enforces a standard of measurement; and a draper is not able to assign any number of inches which he pleases to a yard; so in the realm of thought we shall have an absolute concept of Good, by means of which we are to test the goodness of any particular action. Since it is absolute and unchangeable it cannot be identified with what seems to be good for a particular man at a given moment, viz. what is useful or pleasant for him, but must be equally applicable to all men at all times ; and so may clash with what seems good at the moment. He thus vindicated the supremacy of absolute Good. We know what this good is1 if we think rightly. Now, no man can desire what is evil or bad for him ; if he does but come to the knowledge of the good, by right thinking, he will follow it. Virtue, therefore, is to be identified with knowledge, and sin with ignorance. Hence the attainment of knowledge is of supreme importance, and consequently, it is necessary to discover the laws of knowledge in general. The littempt which Socrates made to do this paved the way for the systematic Logic of Aristotle. He thus brings within the realm of philosophy three regions unclaimed, and unexplored., by it before : the investigation  of the essences or natures of things, the enquiry into the workings of the human mind, and the discussion of right conduct for man. It remained for Plato and Aristotle to perfect and systematise his investigations in these three regions, and so to develop fully what are now known as the sciences of Logic, Psychology, Metaphysics and Ethics.
A short account of the work of these two great thinkers is required in order that we may have a comprehensive idea of what philosophy meant to the Greeks.
Though Plato is one of the greatest philosophers in the history of the world, his genius and originality did not only, or even chiefly, consist in the introduction of new ideas; but rather in the co-ordination and transformation of the work of the earlier thinkers. What is true of Plato in this respect is true also of all the great philosophers, with the possible exception of Kant. Their originality always shows itself rather in the new perspective in which they viewed the problems which had been discussed by their predecessors, and the developments which they gave to them, than in the propounding of novel doctrines. At the first glance, the history of philosophy seems to be but a record of conflicting opinions without any unity; but a closer scrutiny will show that there has been all through it a development of certain great central ideas, though, of course, with setbacks and aberrations. All the great philosophical systems have their roots deep in the past, and embody a uniform tradition, This tradition is first found clearly and explicitly in Plato and Aristotle; and consequently this philosophy has rightly been called the ' philosophia perennis.'
So Plato, standing as it were on the shoulders of Parmenides and Socrates, sees even more vividly than they had done, that the philosopher's work is to contemplate being, and the essences of things. Now the characteristic of these essences is that they are universal. The idea and the nature of Man, of Triangle, and so on, apply to all men, all triangles, regardless of their individual differences. But Plato asks: are these ideas merely in our minds, or have they some reality  apart from them ? He is convinced that they have, though not in the world known by the senses, for there they are found particularised and limited. Thus he concludes that their reality must lie in some super-sensible world where the Man-in-Himself, the Triangle-in-Itself must subsist in their own right. This the realm of the Ideas which alone is truly real: and it follows that the individual things which we see and handle are not real except in so far as the Ideas are reflected in them. They are feeble and deceitful copies of reality, and the object, not of science, but of opinion. They are a number of mirrors reflecting images in the sky, and indeed distorting ones, such as those convex and concave ones seen at fairs ; for matter, indeed, distorts the Ideas— the Reality itself is immaterial—matter is illusory, and is, in a sense, that which is not. This theory of the Ideas involves consequences in other directions ; and especially in Psychology. For if, as is the fact, we have knowledge of the Ideas, this knowledge cannot have come to us by way of the senses, which tell us only of the illusory material phenomena, and must, therefore, have come directly from the Ideas themselves, i.e. the Ideas must be already in our minds before we begin our sense life, before we were born. In a former life, before the soul was imprisoned in the body, it contemplated the Ideas, and has brought fragments of this knowledge with it into the world.
Our birth is but a sleep and a forgetting; The soul that rises with us, our life's star, Hath had elsewhere its setting, And cometh from afar.
We are thus led to a psychological dualism—man is a soul, or mind, forcibly united to a body. Plato, therefore, appears first and foremost as a metaphysician, considering the fundamental reality and being of things ; his psychological and cosmological theories being, in the main, corollaries which followed from his metaphysical one. Nevertheless, he did not regard metaphysics as mere speculation, for he had a profound belief that, by philosophy, man can be enabled to live the perfect life. Thus he expanded  (and amplified the moral teaching of Socrates, showing that ' the good life ' is to be found, not in pleasure, nor even in virtue, but in union with the Idea of Good; and it is to this that metaphysical contemplation is directed. So, in the light of his metaphysical principles, he discusses individual and social morality, and the constitution of the perfect society or Republic, where, since the parts are for the good of the whole, all the individuals will be absolutely subordinated to the State.
For our purpose, which is to discover the nature of philosophy from the conceptions which the great Greek thinkers formed of it, it will not be necessary to set out in detail the various doctrines with which Aristotle enriched it; but it is sufficient to show that, in his view, the aim of philosophy is to get to the very heart of things ; his doctrine, wide as it is in its scope, being still more remarkable for its profundity. The subject of philosophy, he says, has always been, is now, and always will be the question what is being, what is substance, or as we should say nowadays, what is reality ? In answering this question, philosophy cannot be satisfied with any reply which leaves some being unexplained; it must reach down to the first causes and reasons of being—of all being, whether material or mental, universal or particular, mutable or immutable. Thus the earlier philosophies had considered material being exclusively; Parmenides and Heracleitus excluded mutable and immutable being respectively ; even Plato had extruded the world of sense and the individual from reality, pronouncing it illusory. So according to Aristotle being is of many kinds, and not all one, as Parmenides would have it. To justify this he works out his great doctrines of the analogy of being, and the categories, which will exclude Pantheism ; of potentiality and act, which will account for motion and change; of the four causes among which the final cause is first and dominant. It is end which makes the agent act, and determines the form or nature of the thing produced, which form in its turn puts its impress on matter, making it of a certain kind. Now the end to be  attained is not something material, but is mental: it is an idea, as is clearly seen in the case of the sculptor carving a statue ; and it is one and the same idea in different states which makes him work, which guides his action, and is embodied in the finished sculpture. Here, then, we see that Aristotle agrees with Plato in asserting that the primary constituent of reality is form or idea, but now it is incarnate in material things, not subsisting separated from them. It is for this reason that Aristotle has been counted as the opponent of Plato: but, though he criticises severely the subsisting forms of Platonism, his aim is not to break down the essential features of Platonic idealism, but rather to complete his master's work. Both agree that reality is fundamentally ideal or mental. Plato, however, since he divorces his Ideas from the world of sense in fact removes all reality from it also, while Aristotle by embodying forms in matter restores reality to material things ; but is obliged to admit that the forms are, when in this state, limited and imperfect. Both form and matter, moreover, owe their very being to the fact that they are directed to the same end, to something other, and more perfect, than themselves, to something which is more detached from matter, more formal and more actual; and so in the last resort to something wholly formal, wholly actual and perfect, which has, therefore, the nature of mind, or rather of thought. This is the Aristotelean God, from which the whole world hangs suspended by desire : Being, which desires nothing but itself, and thinks nothing but itself, for it is wholly perfect. It is in this way that Aristotle arrives at the ultimate cause and ground of all reality : to search for which is, in his view, the proper business of philosophy.
Since the Thomist philosophy, with which we are to deal, owes more to Aristotle than to any other single thinker, it may not be out of place to add a few details with regard to the life of the man whom S. Thomas calls, without qualification, the Philosopher. Aristotle was born in 385-4 B.C. at Stagira, a seaport of Chalcidice. His father was court doctor to the King of Macedonia, but died while his son was still a boy. He was later sent by his guardian to study at Athens,  where, at the age of seventeen, he joined the Academy- Plato's school there. Here he remained as Plato's pupil and disciple till the latter's death. He was twice married, and for five years was tutor to Alexander the Great. Possibly it was his life at court which made him more careful of his personal appearance than are the generality of philosophers, for it is said that he was noticeably well-dressed. On Alexander's succession to the throne of Macedonia he returned to Athens, where he established a philosophic school in a place called the Lyceum. Here his habit of walking up and down among the trees, discussing abstruse philosophical questions with his pupils, gained the name of Peripatetics for his disciples. In the evening he explained less difficult subjects to a larger audience. In 323 there was an outburst of anti-Macedonian feeling at Athens: and Aristotle, having been so closely associated with the Macedonian court, was in some danger. He therefore retired to the fortress of Chalcis; to prevent the Athenians committing another crime against philosophy, as he said, referring to the execution of Socrates. He died at Chalcis in the following year.
We are now in a position to draw together the facts which we have noted in our account of the genesis of philosophy, and so to determine what philosophy really was in the time of the Greeks ; which will tell us what it is, in its essence, to-day. Now it is evident, in the first place, that all these investigators were seeking, not a method of making or doing something, as an artist or an engineer might be, but some sort of knowledge. Knowledge in itself, and for its own sake, seems to be their aim, and they range over a wide tract of country in their hunt for it. The Ionians want to know what the material world is made of; and answer: material stuff of one sort or another, which is the uniform basis of all bodies. The Pythagoreans, in answer to the same question, say it is a universal quality of matter : the Eleatics, examining it more searchingly still, say it is the unchangeable being of matter; Heracleitus, the constant movement and becoming of it. Empedocles and the Atomists try to reconcile  these last two answers, while Anaxagoras points out that there is something in the material world which is not material, viz. order. This must tend to some end and be produced by some mind. So for the first time a new field is opened up for examination by philosophy : it must know what mind is. But man has mind, says Socrates, so philosophy must ask what man is. With Plato the interest of philosophy centres in this question of the nature of mind, and of concepts—of the immaterial; while with Aristotle the balance is restored and material nature, man, mind and God all come within the scope of the enquiry.
None of these men, it is to be noted, tried to answer these questions by an appeal to any revelation, to myth, or religious knowledge of any kind; but attempted to extract the answer by using their reason; and they used it almost without reference to sensible observation and experiments. Why was this ? Clearly because they were convinced that the thing they sought lay deeper in the heart of the world than the superficial aspect of things, of which alone the senses could tell them. They were seeking the underlying causes of things, and this is the special point of view from which philosophy discusses its multifarious objects, which are dealt with from another aspect, by special sciences, such as chemistry, biology, zoology, and so on. It intends to go further into their nature than these do, and not to rest content until it has uncovered the absolutely fundamental reasons of them all. Thus the early philosophies were not concerned to find out, e.g., of what the world, as at present constituted, is composed, as chemistry is; but what were its primary constituents: or again, in the case of man, they were not concerned, for example, with his anatomy, but whether, in the last resort, he is spiritual or material, intelligent, and so on. So philosophy is distinguished, on the one hand, from any knowledge which may be gained through religion; and on the other, from that which may be gained from what we now call the Natural Sciences. Secondly, it uses in its investigations only natural reason, not faith, nor yet sensible experience as such. Thirdly, it excludes nothing from its examination, but includes all things in heaven and  earth, man and God, in its enquiry; and yet is distinguished from all the special sciences which study any of these things, by its special point of view, which is to discover the basic reason of all: and thus philosophy is not to be identified with any of them singly, or all of them together. All this can be summed up in the one phrase, which is the real definition of philosophy : It is the scientific knowledge of all things gained through consideration by the natural light of reason, of their fundamental reasons or causes.
Books to consult
- W. STACE, A Critical History of Greek Philosophy. (Macmillan.) To which the foregoing account owes much. It also includes a discussion as to the nature of philosophy.
- J. MARITAIN, Introduction to Philosophy. (Sheed and Ward.)
- BURNET, Early Greek Philosophy. (Macmillan.)
- W. D. Ross, Aristotle. (Methuen.)
- A. E. TAYLOR, Plato: the Man and his Work. (Methuen.)
- Phillips: THE DEMONSTRABILITY OF THE EXISTENCE OF GOD
- Phillips: Individuation
- Commentary on the Metaphysics by Albertus Magnus
- Commentary on the Metaphysics by Thomas Aquinas, book I.