The bulk of Aristotle’s writings consists of unpublished treatises that were either Aristotle’s lecture notes or used as texts by his students. Of the dialogues and other works that Aristotle published during his life only fragments quoted by later writers have “survived”. The treatises that survive have traditionally been regarded as expounding a finished system of doctrine.

It is only in 20th century that scholars have tried to discern development within Aristotle’s writings. First attempts at tracing this development were guided by the assumption that Aristotle must have begun as a loyal Platonist and become more critical of Plato as he developed.

More recent assessments find a hostility to Plato’s philosophy in what are reckoned to be Aristotle’s earliest treatises and detect the evolution of a more sophisticated position which, while by no means Plato’s, is nevertheless closer to Plato’s in spirit.

In Metaphysics  (A9 and M4-5) Aristotle explicitly criticizes Plato’s theory of Forms, alluding to the “third man argument”[1] and complaining that the Forms are useless as explanatory devices and that the various arguments for accepting the Forms either prove nothing or establish the existence of unwelcome Forms such as negations and relations.

Even where Plato’s Forms are not the target of criticism, Aristotle advances theories that run contrary to the drift of Plato’s thought. This is true particularly date from Aristotle’s days in the Academy.

In the Categories individual things such as particular men and animals are called primary substances; species and genera of primary substances are called secondary substances. In claiming that individual things are primary realities Aristotle has stood on its head Plato’s view that sensible particulars are only partly real’ pale reflections of the full reality which is described by giving an account of what such particulars inadequately imitate.

Aristotle adds that it is characteristic of both primary and secondary realities (substances) not to have contraries. Many of Plato’s Forms come in contrary pairs, for example, the large and the small. Aristotle would not classify the large and the small as substances. These belong to one of nine other categories (in this case the category of relation).

In the Posterior Analytics, Aristotle argues for the autonomy of various disciplines and against there being principles common to all sciences, from which the correct explanations given in those sciences could be deduced. Acceptance of this would undermine the hope that Plato, held of dialectic.

Aristotle never accords to dialectic the dignity of “the coping stone of the sciences”, but like Plato his thought was profoundly shaped by his involvement in the peculiar debating activity which for Plato was the beginning of dialectic.

Dialectic led Aristotle to a formal theory of valid inference built around the syllogism. It also led him, though the need to spot equivocation [2].

One device for detecting equivocation was also put to work reinforcing the frontiers between autonomous disciplines. The facts and explanations pertaining to different kinds of things belong to different sciences.

Combined with the categories, this principle provided further ammunition for attacking Plato’s project of a master science.

Thus there is no single kind which is everything there is, and there is therefore no science which encompasses everything there is. Plato says dialectic studies either Being or the Good, but ‘to be’ and ‘good’ are used in several categories and are therefore not univocal.

This argument appears in Eudemian Ethics (1.8) but the line is softened considerably in Metaphysics 1 where Aristotle allows that a single science may encompass things that are systematically related in ways other than as species of a single genus.

The categories show how various things that are said to be (quantities, qualities, relations, e.t.c.) are related to substance and so there is, after all, the possibility of a discipline that studies everything that is.

 Aristotle calls this discipline ‘First Philosophy’, although the treatise devoted to it came later to be known as the Metaphysics. Undertaking an enquiry into First Philosophy represents something of a concession to Plato.

Dr. Konstantina Palamiotou-Thomaidou

Phd. of Philosophy, University of Athens


.[1] The whole theory of Forms of the third Plato’s period is subjected to a searching examination in the Parmenides. It is hard to estimate Plato’s own view of the criticisms raised there . The most famous, known as the “third man argument” depends essentially on a motivation for the Forms, known as the “ the one over many principle” which Plato mentions in only one other place.

. Equivocation: [2] To employ equivocal words or expressions, confounding their meanings.