This book is intended to help the student to discover and explore Aristotle. Most people would agree that he is not an easy philosopher to approach. His treatises cannot be read for enjoyment purely as literature, as many of Plato's dialogues can, and the man behind the treatises has the reputation of being a dry, uninspiring, even rather inhuman, person. If in the popular view Plato is as much a poet as a philosopher, Aristotle is still generally thought of first and foremost as a dogmatist and systematiser. This account of him, which is largely the product of a tendency to confuse Aristotle with Aristotelianism, is grossly exaggerated. Like Plato, he conceived the business of philosophy to consist as much in the defining of problems, the examining of alternative views, and the exploring of difficulties, as in the propounding of solutions, and his thought, like Plato's again, underwent a gradual evolution, even though this is, in his case, much more difficult to reconstruct owing to the nature of our evidence.

But while Aristotle is neither as unimaginative nor as inflexible as he is sometimes represented, no one can deny that his thought is often opaque. The treatises make slow and difficult reading, although their difficulty arises as much from the complexity and subtlety of their ideas as from the obscurity of Aristotle's expression. Yet however daunting the texts appear, there is no substitute for a close study of Aristotle's own words to grasp his philosophy.

The transmission of movement

The ultimate source of movement, in Aristotle's system, is the unmoved mover who acts as a final cause, by being loved. The ‘moved movers’—the heavenly bodies or more properly the spheres that carry them—transmit movement in turn as efficient causes. But whereas throughout the heavenly region movement is eternal and unchanging, in the region below the moon there is both movement and change. Change is brought about primarily because the course of the sun in the ecliptic is oblique to the axis of the earth. This oblique course of the sun causes the changes in the seasons, the ceaseless pendulumlike movement between the two extremes of the heat and dryness of summer and the cold and wet of winter, changes which are, of course, a good deal more striking in the Mediterranean than they are in our own more temperate climate.

In making the sun the source of change in the sublunary region Aristotle was no doubt chiefly influenced by the manifest fact that the generation and decay of many living things, especially plants, are closely linked with the seasons. There are, however, several serious difficulties both in his view of the relation between the heavenly and the sublunary regions, and in his theory of the transmission of movement from one to the other, and these must be considered before we discuss his account of the sublunary region as a whole.

Programme and methods

The last chapter of the Nicomachean Ethics points out that it is only by good legislation that society can ensure the good conduct of its citizens. The study of the behaviour of the individual is continuous with the study of society as a whole, and Aristotle mentions some of the main questions that need to be investigated under the second head. He complains that his predecessors had left the topic of legislation unexamined and he sketches out how he will deal with the subject. First he will review earlier ideas where they seem to have something to contribute to the subject. Then he will investigate, ‘in the light of the constitutions that have been collected’, what factors preserve or destroy constitutions and the reasons that some states are well, others badly, governed. Finally he will consider what constitution is best and what laws and customs the best state should have (EN 1181 b 12–23).

From the programme outlined here one might suppose that Aristotle undertook the detailed histories of individual constitutions, such as the Constitution of Athens, before writing the Politics, in which he deals with the causes of the changes in constitutions, the best possible form of state and so on. It might even appear that he followed, or claimed to be following, an idealistic work-plan, first completing the descriptive studies, and then and only then proceeding to the theoretical treatise.

Discussing the growth of Aristotle's thought, I argued that there is an important continuity in his development Naturally his views on many questions, including, for example, such a fundamental problem as the ultimate source of movement in the universe, changed during the course of his life, and he certainly also developed important, and engrossing, new interests. But whether any drastic revolution took place in his thought is doubtful.

Even his rejection of the teaching of Plato was not a matter of a simple, sudden and dramatic break so much as a complex, gradual and continuing process. His disagreements with his master date from early in his career and for some time after he had rejected the theory of Forms he still considered himself a member of the circle of Platonists. Conversely, long after his links with the Academy had become rather tenuous, there remained much in common between his mature philosophy and Plato's. Moreover while in zoology, for example, he pioneered a new approach to the study of the animal kingdom, his detailed investigations in that field tended to endorse certain doctrines, such as that of the final cause, that owe an obvious debt to Plato. Aristotle's work was wider-ranging and more original than that of any earlier philosopher, indeed of any philosopher of any time, but certain methodological assumptions and key ideas underlie a great deal of his thought.

Three separate ethical treatises are included in the Aristotelian Corpus, the Magna Moralia, the Eudemian Ethics and the Nicomachean Ethics. Of these the Magna Moralia is far from certainly authentic. Some scholars consider it an early work, composed while Aristotle was still much influenced by Plato, but it is more usually thought to have been written by one of Aristotle's pupils. Of the two other ethical treatises the Eudemian Ethics is generally held to be the earlier and it is useful both for the additional evidence it provides concerning some of Aristotle's ethical theories and more especially for the light it throws on their development. Our main source for his mature moral philosophy is, however, the Nicomachean Ethics, and it is with this that I shall be chiefly concerned in this chapter.

The plan of the ‘Nicomachean Ethics’

This is one of the most coherent and systematic of Aristotle's treatises and it is probably the easiest and most rewarding of all the major works for the student to tackle first. Unlike the Physics and the Metaphysics, which are collections of books that are often quite loosely connected to one another, the Nicomachean Ethics forms a coherent whole. Aristotle defines the subject and states the problem in book i. Books ii to v deal with moral virtue, first in general, then, after a discussion of choice and responsibility, in detail. Book vi deals with intellectual virtue, vii with moral weakness.

Aristotle nowhere puts forward a developed aesthetic, nor even a complete theory of literary criticism. Yet despite the gaps and limitations of his discussion and the extreme obscurity of some of his ideas, he went further in his analysis of the aims and nature of poetry than any earlier writer. His defence of the usefulness of poetry provided an important antidote to Plato's criticisms and rejection of it, and his work in this field was to prove enormously influential.

The ‘Rhetoric’

He discusses literary style in two treatises, the Poetics and the less well known Rhetoric. To deal briefly with the Rhetoric first, that work, as its name suggests, is an analysis of the art of public speaking. The scope of rhetoric and its relation to philosophy had been topics of some dispute which Plato had discussed at length in the Gorgias and the Phaedrus. Aristotle defines it as the faculty of discovering the possible means of persuasion with regard to any subject (Rh. 1355 b26f.). It is a counterpart to or offshoot of dialectic, which he had discussed in the Topics. Both deal with probabilities, and as such they are both contrasted with the study of strict demonstration or scientific proof, the subject-matter of the Analytics. But while dialectic proceeds by question and answer, the orator uses continuous speech, exercising his skill in three main fields: (1) political, (2) legal, and (3) ceremonial, oratory.

In many ways Aristotle's doctrine of the ψΥχή is the linchpin of his whole philosophy: certainly it is the key to his philosophy of nature and it provides an important link between his physics, his ethics and his theology. Of all natural objects, it is those that are alive that provide the clearest and most dramatic illustrations of the role of the final cause—the young animal and the seed of the plant growing into mature specimens. The doctrine that different living creatures possess different vital functions plays, as we shall see, an important part in his conception of happiness: happiness and the good for man are defined in terms of the activity of the ψΥχή, but particularly in terms of that faculty which man alone among the animals possesses, namely reason. So the highest activity for man is the activity of reason, contemplation. Living creatures are arranged in a hierarchy according to the faculties of the ψΥχή they possess, and this scale extends upwards to include the gods. While men have reason along with other, lower faculties of the ψΥχή, the gods possess reason alone, and the activity of the unmoved mover is, as we have seen, described as continuous untrammelled contemplation.

Conventionally, translated ‘soul’, the term ψΥχή has a range far wider than either ‘soul’ or ‘mind’ in English, for it covers every vital function from reproduction, through sensation and locomotion, to reason.

Aristotle was born in 384 b.c. at Stagira, a small town in Chalcidice in northern Greece. His father Nicomachus was court physician to Amyntas, King of Macedon. A modern reader may be surprised that it was an otherwise quite undistinguished city-state, and not Athens or one of the other major cultural centres of Greece, that produced Aristotle. But many brilliant Greek philosophers and scientists came from cities which were of secondary economic importance. The atomist Democritus, for instance, came from Abdera, another small town in northern Greece not far from Stagira. Although Aristotle spent more than half his active life in Athens, he never became an Athenian citizen, and his connections with Macedonia were to prove an embarrassment to him, indeed after the death of Alexander the Great a danger to his life.

The fact that Aristotle's father was a medical man is not without importance, since it suggests that Aristotle was introduced to Greek medicine and biology at an early age. Although we have no information concerning the type of medicine that Nicomachus himself practised or professed, two of the most famous of the so–called Hippocratic treatises demonstrate that at least one notable representative of Greek scientific medicine was at work in northern Greece at the end of the fifth century b.c. These are the first and third books of the Epidemics, which contain casehistories collected from such places as Thasos and Abdera.

The first part of this study has been devoted to giving the outlines of Aristotle's intellectual development. In the second I shall take the main branches of his work in turn and attempt to describe and elucidate the fundamentals of his thought, locating his principal ideas in the context of the philosophical and scientific discussions of the time, and assessing their value and importance. The first general field I shall consider is logic. Here his work is particularly comprehensive, very largely original and for the most part eminently lucid. It is, moreover, highly professional, and the specialist will find a great deal that is of interest in the logical treatises apart from those sections of them that contain what still remains an excellent introduction to the study of elementary logic. For the sake of illustrating his work in this field, however, it will be enough to select three topics for particular comment, his doctrine of categories, his syllogistic and his conception of so–called ‘scientific’ knowledge.

The logical treatises, known collectively as the Organon or ‘tool’ of thought, begin with two short works, the Categories and the de Interpretatione, dealing with terms and with propositions respectively. The first chapter of the Categories, for example, begins by drawing distinctions between things named (1) ‘homonymously’, (2) ‘synonymously’ and (3) ‘paronymously’. Things are named ‘homonymously’, first, when they have only the name in common and the definition corresponding to the name is different in each case.

The range of ‘physics’

As ϕΎσις is simply the Greek word for nature, ϕΥσική is much wider than our ‘physics’, for it is the science of nature as a whole. Natural objects are those that have a capacity for change or movement within themselves, and ϕΥσική is the science (1) of such natural changes and movements, and (2) of the changing or moving objects themselves. It comprises, on the one hand, the study of things that are in eternal, unchanging movement—the heavenly bodies—and, on the other, the study of things that are subject to change and variation, both living creatures and inanimate objects, the elements and their compounds. The ‘physicist’ investigates, for example, the ultimate constituents of matter, the modes of combination of the elements, and their natural movements. Besides astronomy, ϕΥσική, in Greek, includes not only the sciences we should call dynamics, physics and chemistry, but also all the various branches of biology.

The general principles underlying Aristotle's account of movement and change have already been outlined in ch. 3. Both the doctrine of the four causes, material, formal, efficient and final, and that of potentiality and actuality are introduced in the course of critical reviews of previous ideas on causation, and the latter doctrine, in particular, enables him to circumvent the problem that had perplexed Greek philosophers since Parmenides, of how anything can be said to change or come to be at all.

Until comparatively recently Aristotelian studies were dominated by the assumption that the doctrines the Corpus contains form a single perfected system. In this, as in many other respects, Aristotle was sharply contrasted with Plato. While Plato's thought was generally recognised—from the early nineteenth century, at any rate—as a complex entity that evolved throughout his life, Aristotle's philosophy was thought of as quite the opposite, a static, dogmatic, monolithic whole. When discrepancies were noted between the doctrines expressed in two different passages in the treatises, the tendency was to assume that one or other passage was corrupt and to emend the text accordingly. So long as Aristotle was treated, as he was throughout the Middle Ages, as a preeminent, if not infallible, authority on most philosophical issues, the possibility that this authority ever changed his mind was not seriously entertained. But even when a more critical attitude towards Aristotle became the rule, it was still generally assumed that his philosophy formed an unvarying dogmatic system, and this assumption was not challenged until well into the present century.

Jaeger's thesis

The major force in what may, without exaggeration, be called the revolution in Aristotelian studies was Werner Jaeger. In 1912 Jaeger produced a study of the development of the Metaphysics, and then in 1923 appeared the first edition of his general work, Aristotle: Fundamentals of the history of his development.