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.

Our analysis of Aristotle's main criticisms of Plato has already suggested thac his reaction against Platonism owes a good deal to his interest in natural science. The realisation of the need to begin the investigation of natural species with the concrete particulars must have deepened, even if it was not the sole cause of, his dissatisfaction with the theory of knowledge advocated by Plato in connection with the Forms. In attempting to document the growth of Aristotle's interests in natural science we have two precious pieces of evidence. First there is the connection which I have already noted between many of the place-names mentioned in the Historia Animalium and the areas of Greece where we know Aristotle lived during the so–called period of the travels from 347 to 335 b.c. The Historia Animalium contains some detailed information about the peculiarities of the animals, especially of the marine animals, found in and around the island of Lesbos, and particularly in the straits and lagoon of Pyrrha on that island, and Pyrrha figures again in the documentation of the two other main biological treatises, the de Partibus Animalium and the de Generatione Animalium. Aristotle's interest in biology no doubt dates from before the time he went to Asia Minor. His father was a medical man, and the problems of classification, particularly of the classification of natural species, were a much discussed topic in the Academy.

So far I have discussed three main features of Aristotle's intellectual development, the influence that Plato had on the young Aristotle, his reaction against the principal tenets of his master's philosophy, and the development of his interests in natural science, particularly in biology. But in concentrating on the main lines of his intellectual development during the earlier part of his life many other aspects of his work have necessarily been neglected. Yet from the beginning the range of problems that engaged his attention was wide, and it is now time to do more justice to this fact before turning to consider the chief characteristics of his work during the final period of his life.

As a young man in the Academy Aristotle would have discussed not only the ontological and epistemological questions connected with the theory of Forms, but also a large number of other subjects which certainly included logic or dialectic, ethics, politics and psychology. In each of these fields criticisms of Platonic theses are the startingpoint of some of Aristotle's own theories, and in some cases these criticisms may well have begun to take shape while he was still Plato's pupil. In logic, for example, the nature of dialectic and the difference between the dialectician and the sophist are discussed at some length by Plato in the later dialogues. Academic debates on these topics undoubtedly provide the background against which Aristotle developed his own complex classification of the different main branches of reasoning, demonstrative, dialectical, rhetorical and eristic, and it is natural to suppose, in this instance, that this analysis is, in the main, a product of the period of his first residence in Athens.

The Natural Image

It was said at the outset that Platonism and Christianism adopted different attitudes towards corporeal nature, the one regarding it as an obstacle to the soul's perfection, the other as an aid, and itself perfectible. The statement requires modification on both sides. Plato in his later works taught that the sensible world, being a copy of the intelligible, was a guide to the understanding of it, and his successors, under the influence of the Asiatic cults, adopted the same attitude to man-made images; while the early Christians, inheriting the Jewish abhorrence of idolatry, regarded as sacrilegious the representation of spiritual things through the medium of matter. Paganism and Christianism reacted to the same stimulus in contrary ways: the pagan cults which infected Platonism with theurgy stiffened the resistance of the Christians and turned their monotheism, for a time, into iconoclasm.

In the sensible world natural images are distinguished from artificial images by their causes. The causes of the former are the Forms: ‘ The Idea’, says Xenocrates, ‘is the exemplary cause of things which subsist naturally (κατα φυσιν).’ The causes of the latter are concepts in the mind of the artist: ‘Every artist possesses wholly the paradeigma in himself, and confers its shape upon matter.’ But if the Forms are themselves concepts in the Divine Mind, then both kinds of cause are concepts or thoughts, and the difference lies in the thinker, in the one case divine, in the other human.

St Augustine's life spanned almost eighty years of a period during which the ‘decline of the Roman Empire’ passed through its most dramatic, if not its most decisive, phase. Born into the Christian Empire of Constantine's successors, his youth saw the brief pagan reaction under Julian the Apostate, followed by the return to Christianity and the ever closer linking of the Empire to Christianity under the Emperors Gratian and Theodosius I. During the latter part of his life Roman paganism, which had rallied its forces during the last decade of the fourth century, was rapidly becoming a relic of the past, though it remained a force to be reckoned with. He witnessed not only an important phase in the Christianization of the ancient world; he also lived through some of its gravest military and political upheavals: the military disaster of Adrianople (378), the division of the Empire after Theodosius, the irruption of Vandals, Sueves and other barbarians into the western provinces of the Empire (406), the increasing barbarization of the Roman armies and of the imperial court, the sacking of the City of Rome by the Visigoths (410). These are some of the landmarks. The Vandal invaders of his own North Africa had just reached his episcopal city of Hippo as he lay on his deathbed. In an important sense his life may be said to coincide with the transition from antiquity to the Middle Ages. Augustine belonged to both worlds, in many ways, and not least intellectually. He received the kind of education which was typical of late antiquity, characterized by a predominantly literary or rhetorical outlook.

A Christian Platonist may be either a Platonist who requires to substantiate his speculations by a faith which transcends them, or a Christian who thinks of his faith, and desires to expound it, in terms intelligible to Platonists. St Augustine is the outstanding example of the former type, with whom could perhaps be associated from among the Greeks the ps.-Dionysius and Johannes Philoponus if we knew more about their origins. But the thinkers who built up the Greek Christian Platonist tradition and kept it within the bounds of orthodoxy mostly belonged to the latter: the Alexandrians, the Cappadocians, possibly the ps.-Dionysius, certainly St Maximus Confessor. And it was by following in the footsteps of these, but particularly of St Gregory of Nyssa, the ps.-Dionysius and Maximus, that Johannes Scottus Eriugena introduced this form of Christian philosophy to the West.

Three attitudes towards pagan learning were possible for the Christian: uncompromising acceptance, which led to heretical Gnosticism; uncompromising rejection, as shown by the early apologists and ascetics, favoured by the School of Antioch, and surviving into the Iconoclastic movement and into some forms of modern protestantism; and controlled acceptance, the attitude of the Alexandrians and of the writers discussed in this Part, which produced the Christian philosophy, or Christianism. This attitude acknowledges that the current philosophical systems contained elements of truth, a fact taken for granted by the Alexandrians and openly asserted, with particular reference to Platonism, by the Cappadocians, while rejecting what is evidently falsified by the Christian Revelation.

Pseudepigrapha

We know no Platonist later than the Old Academy and earlier than Eudorus who would have been interested in the Two-opposite-principles doctrine and the attendant horizontal stratification as attributed to Plato by Aristotle. Plutarch, who quotes Eudorus in a different context, knows the doctrine but makes very little of it. However, this does not mean that the doctrine was, before Eudorus, forgotten altogether. It rather seems that, while it lost its home in the Academy (or was relegated to some corner there), it was fully appropriated by the authors of post-Platonic Pythagorean writings. However, they often equate the two principles with Aristotle's form and matter, or with the active and passive principles of the Stoa. Syncretism makes its full appearance.

For our purpose it is best to distinguish three classes of these writings. The first consists of pseudepigrapha. Two names are of particular interest in this group: that of Ps.-Archytas and that of Ps.-Brontinus (assuming the passage by the latter as quoted first by Syrianus, and the passage by the former as quoted by Joh. Stobaeus to belong to the pre-Plotinian period).

Speaking of Brontinus, Syrianus assures us that the Pythagoreans were familiar with the doctrine that there is a principle higher than the two opposite principles. To prove it he quotes Philolaus as having said that God brought forth limit and the limitless; and he says that Archaenetus (there is hardly any reason to change this to Archytas) spoke of a cause prior to a cause and that Brontinus said of this cause that it is above intelligence and being (ousia), surpassing it in power and dignity.

The discussion on the character of Boethius: Platonic or Christian philosopher?

The impetus given to speculative thought by the existence of a court interested in intellectual activities petered out with the beginning of the tenth century. The invasions destroyed a good deal of the economic presuppositions on which centres of learning had to rely, and interrupted their lines of communication. There is good reason for the name of the ‘Dark Age’ given to the decades which followed the end of Carolingian civilization. While the importance and influence of the French monarchy was reduced by the rise of feudal principalities, and remained so during this period, after 950 the Ottoman dynasty were capable of re-establishing monarchical power in Germany and of reviving literary activities as the true heirs of Charlemagne. Under their rule Latin writing in prose and verse was cultivated in those Saxon lands where Christianity had been introduced only a few generations earlier. But their court never reached such importance as a forum where speculative questions were debated as had distinguished the circle of scholars round Charlemagne and his grandson. Single centres in West and Central Europe kept up a certain continuity of philosophical learning. In some monasteries and cathedrals the libraries, collected under the impulse of the Carolingian revival, were preserved, and so the tradition of study, linked to the keeping and copying of manuscripts, remained alive. Some of these books, handed on from antiquity, raised disturbing questions about the relationship of rational thought to Christian revelation in the mind of the monk or canon who read them.