"The greatest thinker of antiquity," Marx called him. Aristotle lived from 384 to 322 B.C., and was born, not in Athens but in Stagira, Thrace. Originally a pupil of Plato, he made a thorough study of his philosophy over a period of twenty years, but evidently became dissatisfied with it. After Plato’s death, he left the Academy and later became the tutor of Alexander. He returned to Athens in 335 B.C., to found his own school, the Lyceum. His was an encyclopaedic mind, encompassing a huge number of subjects—logic, rhetoric, ethics, political sciences, biology, physics and metaphysics ("what comes after physics," the study of first principles and presuppositions). He is the real founder of logic, natural history, the theory of morals, and even of economics.
The philosophy of Aristotle marks a sharp break with that of Plato. In many ways it is diametrically opposed to it. Instead of the idealist method, which turns its back upon reality in order to take refuge in a world of perfect ideas and forms, Aristotle proceeds from the concrete facts of sense perception, and from these arrives at ultimate grounds and principles. Whereas Plato started with ideas, and tried to explain reality from them, Aristotle sets out from reality, carefully examining a large number of facts and phenomena, in order to derive from them a series of general inferences. That is to say, he used the method of induction.
Aristotle’s interest in physics and biology is an illustration of his general approach, his love of experiment and observation as the main source of knowledge. In this, he was a pioneer of the modern scientific method. When Alexander the Great was engaged on his wars of conquest, he arranged to send back to Aristotle details and drawings of all new discoveries of plants and animals. What a difference to Plato, who regarded the crude material world of nature as unworthy of his attention! Aristotle spent many years collecting, arranging, and classifying information from all manner of spheres.
Aristotle, however, did not merely collect facts. Basing himself on information derived from the objective material world, he proceeded to generalise. In his most profound work, the Metaphysics, he speculates on the meaning of universal notions. In the process, he sums up and criticises previous philosophies, and therefore may also be regarded as the first historian of philosophy. It should be borne in mind that this has nothing to do with the use of the word "metaphysics" in the writings of Marx and Engels, where it is used in an entirely different sense—as a way of describing the narrow mechanical outlook of the non-dialectical materialist philosophers of the 18th and 19th centuries. In fact, the "metaphysics" of Aristotle occupies a similar place to dialectics in the philosophy of Plato.
In the Metaphysics, Aristotle for the first time provides a systematic account of some of the basic categories of dialectics. This fact is often overlooked, because he also laid down the laws of formal ("Aristotelian") logic, which, at first sight, appear to stand in contradiction to dialectics. In point of fact, for Aristotle, logic and dialectics were both valid ways of thinking. This is, in fact, the case. Dialectical thinking does not contradict formal logic, but complements it. More correctly, the laws of formal logic hold good within certain limits, beyond which they break down. In particular, formal logic, based on the law of identity, cannot adequately deal with motion, which involves a contradiction—something which formal logic explicitly rules out. For a whole series of operations in everyday life, the rules of formal logic hold good and play a useful role. But when the attempt is made to apply these laws and thought-forms to areas where they conflict with reality, they turn into their opposite. Far from helping us to understand the workings of nature, they become an endless source of error, holding back the development of science and knowledge.
The whole of formal logic is based on three propositions, which make up the basic Aristotelian syllogism:
1) the law of identity ("A" = "A")
2) the law of contradiction ("A" is not "not-A"), and
3) the law of the excluded middle ("A" is not "B")
For more than 2,000 years, this has been the corner-stone of all logic. Towards the end of the 18th century, Kant was able to say that logic, since Aristotle, had not made any step forward or any step back. Despite all the changes experienced by science in that period, the rules of logic remained petrified, in the forms worked out by Aristotle, and later converted into a dogma by the mediaeval Church. Yet the basic Aristotelian syllogism upon which the whole edifice is constructed is based on a false premise. In the first place, despite the appearance of a logical progression, this is an illusion. All three assertions are, in fact, already contained in the first one, "A" is "A." Everything stands or falls with this, the "law of identity."
At first sight, the truth of this proposition would appear to be self-evident. Like the law of contradiction, which is merely a negative way of saying the same thing, it seems to brook no dissent. "There are some who maintain (a) that the same thing can be and not be, and (b) that it is possible so to judge. Many physicists too, have used language to this effect. Now we have just assumed that a thing cannot both be and not be, and have also shown this to be the most indubitable of all principles. The demand that we should prove the law argues a defective education in logic—a science which enables one to recognise what requires proof and what does not. It is absolutely impossible to have proof of everything: the process would continue indefinitely, and the result would be no proof of anything whatsoever. Granted, on the other hand, that there are some things which do not call for proof, what principle, I ask, is more self-evident than the law of contradiction?" (Aristotle, Metaphysics, p. 125.)
It is interesting to note that here Aristotle, who is normally most concerned to prove each of his postulates by a rigorous process of argument, makes no attempt to prove the law of contradiction, but merely asserts it dogmatically. It is just to be accepted as "common sense." But, upon closer examination, the matter is not at all as simple as it is presented. In real life, a thing is and is not equal to itself, because it is constantly changing. You are in no doubt that you are you. But in the time you have taken to read these lines, billions of changes have taken place in your body—cells have died and been replaced. The body consists of tissue, which is constantly breaking down and being replaced, eliminating waste matter and bacteria, excreting carbon dioxide through the lungs, losing water in sweat and urine, and so on. These constant changes are the basis of all life. They mean that, at any moment, the body is itself and also something different to itself. So you are not the same person you were. Nor is it possible to get round this by arguing that you are you at this precise moment in time, since even in the smallest portion of time, change takes place.
For normal purposes, we can accept that "A = A," that you are you, and nobody else. The reason is that the kind of change we are referring to is so small that it can be ignored for normal purposes. However, over a longer period, twenty years, for instance, a difference would be noticed. And in a hundred years, the difference would be quite sufficient for one to conclude that you are not you at all! Moreover, this does not only apply to living things. Inorganic matter is also in a state of constant change, so that everything is and is not, because, to use Heraclitus’ marvellous expression "everything is in flux."
For ordinary everyday purposes, we can accept the law of identity. Indeed, it is absolutely indispensable, if thought is not to dissolve into utter confusion. But for more accurate calculations, or higher velocities approaching the speed of light, or for a whole series of critical situations, it proves inadequate. At a certain point, an accumulation of small, quantitative changes gives rise to a fundamental change in quality. All of this remains a closed book to formal logic, the fundamental weakness of which is an inability to deal with things in their movement and life.
Similarly with the law of the excluded middle, which states that it is necessary either to assert or deny, that a thing must be either black or white, either alive or dead, either "A" or "B." It cannot be both at the same time. For normal everyday purposes, we can take this to be true. Indeed, without such assumptions, clear and consistent thought would be impossible. In the period of decadence of sophism, it became customary to play with dialectics in an arbitrary way, which so twisted the method of reasoning as to be able to prove practically any opinion. Aristotle was determined to clear up the mess caused by the subjective dialectics of sophism, hence his insistence on elementary logical propositions.
Nevertheless, when we depart from the realm of everyday experience and consider more complex processes, it is by no means such a simple matter to distinguish "A" from "B." The dogmatic insistence on eliminating contradiction leads precisely to the metaphysical mode of thought in the specific sense understood by Marx and Engels, as explained in Anti-Dühring, which points out the limitations of the laws of formal logic when faced with the contradictory reality of nature:
"To the metaphysician, things and their mental images, ideas, are isolated, to be considered one after the other and apart from each other, fixed, rigid objects of investigation given once for all. He thinks in absolutely unmediated antitheses. ‘His communication is ‘yea, yea; nay, nay’; for whatsoever is more than these cometh of evil.’ For him a thing either exists or does not exist; a thing cannot at the same time be itself and something else. Positive and negative absolutely exclude one another; cause and effect stand in a rigid antithesis one to the other.
"At first sight this way of thinking seems to us most plausible because it is that of so-called sound common sense. Yet sound common sense, respectable fellow that he is in the homely realm of his own four walls, has very wonderful adventures directly he ventures out into the wide world of research. The metaphysical mode of thought, justifiable and even necessary as it is in a number of domains whose extent varies according to the nature of the object, invariably bumps into a limit sooner or later, beyond which it becomes one-sided, restricted, abstract, lost in insoluble contradictions, because in the presence of individual things it forgets their connections; because in the presence of their existence it forgets their coming into being and passing away; because in their state of rest it forgets their motion. It cannot see the wood for the trees. For everyday purposes we know and can definitely say, e.g., whether an animal is alive or not. But, upon closer inquiry, we find that this is sometimes a very complex question, as the jurists very well know. They have cudgelled their brains in vain to discover a rational limit beyond which the killing of the child in its mother’s womb is murder. It is just as impossible to determine the moment of death, for physiology proves that death is not a sudden instantaneous phenomenon, but a very protracted process.
"In like manner, every organic being is every moment the same and not the same; every moment it assimilates matter supplied from without and gets rid of other matter; every moment some cells of its body die and others build themselves anew; in a longer or shorter time the matter of its body die and others build themselves anew in a longer or shorter time the matter of its body is completely renewed and is replaced by other molecules of matter, so that every organic being is always itself, and yet something other than itself.
"Further, we find upon closer investigation that the two poles of an antithesis, like positive and negative, are as inseparable as they are opposed, and that despite all their opposition, they interpenetrate. In like manner, we find that cause and effect are conceptions which only hold good in their application to the individual case as such; but as soon as we consider the individual case in its general connection with the universe as a whole, they merge, they dissolve in the concept of universal action and reaction in which causes and effects are constantly changing places, so that what is effect here and now will be cause there and then, and vice versa.
"None of these processes and modes of thought fit into the frame of metaphysical thinking. But for dialectics, which grasps things and their conceptual images essentially in their interconnection, in their concatenation, their motion, their coming into and passing out of existence, such processes as those mentioned above are so many corroborations of its own procedure." (Engels, op. cit., pp. 26-7.)
It is unfortunate, but not unique, that the brilliant, original thought of a genius became ossified and impoverished in the hands of his successors. The flexible, dialectical aspect of Aristotle’s method, with its emphasis on observation and experiment was lost sight of for a long time. The mediaeval Schoolmen, interested only in providing an ideological basis for the doctrines of the Church, concentrated on his logic, interpreted in a lifeless and formalistic way, to the exclusion of practically all else. Thus, a body of ideas which ought to have provided a healthy stimulus to the development of science, was turned into its opposite—a set of chains for the intellect, which was only shattered by the revolutionary upsurge of the Renaissance.
There is something profoundly ironical about the hijacking of Aristotle by the Church. In fact, his writings are impregnated with a strongly materialist spirit. Lenin considered that "Aristotle comes very close to materialism." (Lenin, Collected Works, Vol. 38, p. 282.) Thus, unlike Plato, in Aristotle, formal logic is closely connected to the theory of being and the theory of knowledge, because he saw the forms of thought as being, not independently existing phenomena, but forms of being, expressed in human consciousness.
Aristotle totally rejected Plato’s theory of ideas as disembodied forms. The aim of science is, of course, to generalise on the basis of experience. But the general only exists in and through the material things given to us in sense perception. He rightly understood the limitations of the early materialists like Thales who attempted to express the material world in terms of a single concrete manifestation, such as water. He saw matter as an eternal substance, which is always changing, which cannot be created or destroyed, with neither beginning or end, but which is in a constant process of change and transformation. One of his main objections to Plato’s idealism is that non-material ("non-sensible") things can have no movement: "But this is quite inadmissible; a heaven…without movement is unthinkable; yet a non-sensible heaven can have no movement." (Aristotle, Metaphysics, p. 94.)
Aristotle’s penetrating mind detected an insoluble contradiction in Plato’s idealism. If there really existed unchanging, eternal forms, how did they succeed in giving rise to the constantly moving, changing material world we see before us? Out of such an immobile idea, entirely devoid of any principle of motion, one can derive nothing at all, except a complete standstill. Nothing comes into being, without a moving force, either from within itself or from without, as Newton found out, when he assigned God the task of providing the initial impulse to get his mechanical universe moving. But here there is nothing of the sort. Plato’s Ideas have no motion in them. But since all things move and change, these allegedly perfect ideas suffer from the greatest imperfection of all. They do not exist. More correctly, they do not exist anywhere except as phantoms in the brains of philosophers.
The absolute separation between thought and being, that peculiar schizophrenia which afflicts all brands of idealism ultimately leads it to impotence, since there is no real way in which the Absolute Idea which is supposed to stand above the world of crude material reality can affect the latter, or impinge upon it in any way whatever. As Schwegler remarks:
"The supporters of the Ideal Theory, then, are not in a position logically to determine any idea; their ideas are indefinable. Plato has left in complete obscurity the relation in general of things to the ideas. He terms the ideas archetypes, and supposes things to participate in them; but such expressions are only hollow poetical metaphors. How are we to conceive this ‘participation’ in, this copying of, these patterns thus remote, absent in an alien region? It is in vain to seek in Plato any definite explanation here. It is wholly unintelligible how and why matter comes to participate in the ideas." (Schwegler, op. cit., p. 104.)
In his struggle against the subjectivism of the sophists, Socrates laid stress on the need to look for universal ideas, and arrive at correct conceptions and definitions which really correspond to the subject matter under consideration. This was an advance as against the arbitrary method of the sophists. Indeed, without such universals, science in general would be impossible. However, Plato’s attempt to transform these general notions into independent entities led straight into the swamp of religious mysticism. What we are really dealing with here, under the heading of "universals" is the genus and species of things. The notion that a genus or species can exist separate and apart from the individuals that comprise it, or vice versa, is a self-evident nonsense. Aristotle rejected the notion that forms and ideas can exist separate from material things:
"While the Ideal Theory involves us in numerous difficulties, its greatest absurdity is the doctrine that there are entities apart from those in the sensible universe, and that they are the same as sensible things except that the former are eternal while the latter are perishable. Those who uphold this view are saying in effect that there is an absolute Man, and Horse, and Hearth. They follow closely in the footsteps of those who teach that there are gods, but in human form; for as the latter merely set up eternal men, so the former do no more than make the Forms eternal sensibles." (Aristotle, Metaphysics, pp. 93-4.)
With enormous patience and intellectual rigour, Aristotle went through all the categories of thought, which he expressed in a far more developed and explicit way than had hitherto been the case. Many of the categories of dialectical thought later developed in Hegel’s Logic are already dealt with in outline by Aristotle—Being, Quantity and Quality, Part and Whole, Necessity and Accident, Potential and Actual, and so on. There are many important insights here. For example, in the discussion of the relation between potentiality ("dynamis") and actuality ("energeia"), Aristotle anticipates the idea of the unity of matter and energy. For Aristotle, matter consists of two aspects, substance, which contains within itself the potential for an infinite number of transformations, and a kind of active principle, "energeia," which is an innate and spontaneous moving force. In developing the idea of the movement of potential being into actual being, Aristotle gives a more concrete version of the "becoming" of Heraclitus. Here we have the main point of difference between the philosophy of Aristotle and that of Plato. In place of the static, lifeless Idea, we have an inherent tendency of matter towards movement and development, which realises itself by constantly passing from potentiality to actuality.
In relation to time, Aristotle shows himself to be superior, not only to Plato, but to many modern scientists, who talk mystical nonsense about the "beginning of time." He points out that time, like motion, has always existed, and that, consequently, it is absurd to talk of the beginning or end of time:
"It is impossible, however, that motion should be generable or perishable; it must always have existed. Nor can time come into being or cease to be; for there cannot be a "before" or "after" where there is no time. Movement, then, is also continuous in the sense in which time is, for time is either the same thing as motion or an attribute of it." (Ibid., p. 342.) This is a profound thought, and one that anticipates the position of dialectical materialism, that time, space and motion are the mode of existence of matter, although Aristotle was unable to develop this idea in a satisfactory way.
Starting out from the position of objective idealism, Aristotle came quite close to materialism, although he never managed to make a complete break; as Lenin comments, he wavered "between idealism and materialism." (Lenin, Collected Works, Vol. 38, p. 286.) In the writings of Aristotle, we find the germs of a materialist conception of history and the development of thought and culture. He explains that, while the actions of animals are determined by immediate sense-impressions (the things they can see, hear, etc.) and memory, only the human race lives by shared, social experience, art and science. While the starting point of all knowledge is experience and sense-perception, that is not enough:
"Wisdom, again, is not to be identified with sense-perception which, though it is our primary source of knowledge of particulars, can never tell us why anything is so (e.g., why fire is hot), but only that it is so." Aristotle, op. cit., p. 52.)
The theory of knowledge of Aristotle also comes close to a materialist position. The starting point is the facts and phenomena given to us through our senses (in sense-perception), passing from the particular to the universal, "so that in this case we have to start from what is more intelligible to ourselves (i.e., the complex facts and objects of experience) and advance to the understanding of what is of its nature intelligible (i.e., the simple, universal principles of scientific knowledge)." (Ibid., p. 172.)
The inconsistency of Aristotle’s position is revealed in the concessions he makes to religion, in assigning to God the role of the First Cause. Anticipating Newton, he argued that there must be something which originates motion, and this something must itself be unmoved. This "something," however, must be an eternal substance and actuality. The concept is ambiguous, rather like the "substance" of Spinoza. It is open to the same objections levelled by Aristotle against Plato. For if the universe was once without motion—something which is impossible—there is no way it could be made to move, unless by an external impulse. But if the "unmoved First Mover" is not material, it is impossible that it should impart motion to a material universe.
Moreover, this line of argument does not solve the problem posed, but merely shifts it back one stage. Let us accept that the "First Cause" set the universe in motion. What caused the "First Cause"? This question is not supposed to be asked. The answer is allegedly given in advance by the phrase "unmoved First Mover," which, of course, answers nothing. The weakness of the whole argument is self-evident, and flows from Aristotle’s preoccupation with the search for final causes (as opposed to what he called material, formal and efficient causes). Within certain limits, for everyday purposes, it is possible to do this with a fair degree of satisfaction. For example, the causes of the existence of a house can be traced to the building materials, the builders, the architect, and so on.
In fact, however, it is possible to go on tracing the causes of even the simplest phenomenon indefinitely. Even in the given example, we could go on to specify the demand for housing, the state of the world economy, the atomic composition of the bricks and cement, the parents and grandparents of all the people involved, and so on and so forth. For practical purposes, we choose not to do this, placing a definite limit on causality. But, in reality, the chain of causation is endless, cause becoming effect, and vice versa, ad infinitum. Thus, the very conception of a "First Cause" is unscientific and mystical. Naturally, this weakest side of Aristotle was seized upon and elevated to the rank of dogma by the Church.
Another misconception in Aristotle, related to the above, was the teleological interpretation of nature. Teleology (from the Greek word telos, an end) holds that all natural phenomena, including man, are determined by an ultimate goal or purpose. This mistaken notion played a negative role in holding back science, since it cannot really explain anything. Moreover, it leads to religious conclusions, because one has to say where this "purpose" came from. The conclusion is drawn that the goal of things is determined by God.
Aristotle himself did not approach things in this way, although it suited the Church later on to give it a religious interpretation. To him, everything contained within itself an active principle, or "soul" ("entelechy"), and the whole of nature is guided by a single supreme goal. This idea probably comes from Aristotle’s investigations of biology. In his works, he mentions some 500 different types of animals, of which he himself dissected about fifty different types. From close observation, he noted how the body structure of animals is perfectly adapted to their environment and mode of existence. From such observations, Darwin arrived at the theory of evolution. But Aristotle drew a different conclusion, namely that the nature of each animal is predetermined by Nature in accordance with a given order, a plan almost, which is inherent in the nature of things. Thus, Aristotle ascribes the body to a divine plan:
"Man alone of all the animals is erect, because his nature and his substance are divine. To think, to exercise intelligence, is the characteristic of that which is most divine. This is not easy if much of the body is situated in the upper part. For weight renders the exercise of thought and perception sluggish. Accordingly, if the weight and the bodily element increase, bodies must bow down to earth; then, for security, nature must substitute forelegs for hands and arms, and we get quadrupeds...But man being erect has no need of forelegs; instead of them nature has given him hands and arms. Now Anaxagoras has said that it is the possession of hands that has made man the most intelligent of the animals. The probability is that it was because he was the most intelligent that he got hands. For hands are a tool, and nature, like an intelligent man, always distributes tools to those that can use them. The proper thing is to give a genuine flute-player a flute rather than to give a man who happens to have a flute the skill to play, for that is to add the lesser to the greater and more august instead of adding the greater and more precious to the lesser. If, then, it is best that it should be so, and if nature, out of what is possible always does the best, it is not because he has hands that man is wise, but because he is the wisest of the animals he has hands." (From Parts of Animals, quoted in Farrington, p. 129-130.)
The idea of Anaxagoras, that the development of human intelligence was made possible by the freeing of the hands was a marvellous insight, but Aristotle completely stands it on its head. His teleological approach prevented him from arriving at a genuinely scientific appraisal of nature, in spite of the vast extent of his researches. Taken over by Thomas Aquinas and the Church, it held back the study of nature for centuries, until Darwin’s discoveries gave a rational explanation of the relative purpose of living creatures. Even so, teleological conceptions in biology resurfaced in different guises—neo-vitalism, neo-Lamarckism, etc. The same tendency is often expressed even today by people who, when attempting to describe natural phenomena, unconsciously endow "Nature" with human characteristics, as if it "made" animals and plants, and got them to behave in a certain way. In reality, the "purposefulness" displayed by plants and animals is the process of optimum adaptation of living objects to their surroundings, and not at all the product of a preordained plan.