To: Pearl K.
From: Geoffrey Klempner
Subject: Aristotle's case for the priority of substance
Date: 9 May 2007

Dear Sachiko,

Thank you for your second email of 9 May with your University of London essay in response to the question, 'Does Aristotle have any good reason for saying that substances are prior to items in other categories?'

You've said not a word more than needs to be said, so far as expounding Aristotle's basic doctrine goes. However, there are two directions in which this essay could be expanded.

The first (as you might have guessed from my boring insistence on interrogating the question) is to ask what Aristotle means by 'prior'. Prior, in what sense?

I can think of several kinds of priority (in no particular order): explanatory priority (you have to explain A in order to explain B as the explanation of A is part of the explanation of B); ontological priority (B exists only in virtue of the existence of A, without A, B could not exist); definitional priority (the definition of A is a component of the definition of B); maybe some vaguer notion of importance or interest (A is more important/ interesting than B) - OK we can discount that. But you get the idea.

Maybe it's obvious to you what kind of priority Aristotle means, but in going through the possibilities you will show the examiner that you know and hopefully write a better essay.

Suppose that Aristotle means ontological priority. Substances are ontologically prior to other items because the other items only exist in virtue of the existence of substances. Of course, if you are being difficult you could say that by the same argument substances only exist in virtue of the existence of qualities, in the sense that there can't be a substance without qualities any more than there can be a quality without a substance to be predicable of.

But this does seem to be along the right lines. Here is where we get to the second way in which the essay could be expanded. In recent times, there has been a strong revival of interest in Aristotle's distinctions. The original 'locus classicus' is the book 'Individuals' by the Oxford philosopher P.F. Strawson, a ground-breaking work came out in 1959.

In 'Individuals' Strawson says he is engaged in 'descriptive metaphysics' which he contrasts with 'revisionary metaphysics'. Descriptive metaphysics aims to lay bare the structure of our conceptual scheme. Aristotle was a descriptive metaphysician in Strawson's view. Revisionary metaphysics, by contrast, tries to show that our common sense understanding of the world as made up of individual things with qualities, occupying space and time is ultimately incorrect - mere 'appearance' - and that in reality the world is, e.g. 'windowless monads' (Leibniz), or a conglomeration of events and processes (Whitehead), or fleeting phenomena (Hume).

Strawson argues for the thesis that spatio-temporal particulars are the basic individuals. The criterion for 'basic' is in terms of the notion of a 'criterion of identity'. We can't say how many whites or how much white there are in the room but we can count the white things. The identification of 'white' depends upon the identification of white things (spatio-temporal particulars).

In the course of his argument, Strawson offers refutations of Leibniz's theory, as well as the theory that a complete description of the world could consist in identifying 'features' at 'places' without first identifying spatio-temporal particulars.

A spatio-temporal particular is Aristotle's 'primary substance'.

Spatio-temporal particulars change over time, while preserving their identity. This aspect is taken up by David Wiggins (originally in his monograph 'Identity and Spatio-Temporal Continuity' and later in his book 'Sameness and Substance'). The identity of spatio-temporal particular is always identity 'under a covering sortal concept'. The old man drinking the hemlock is the 'same man' as the youngster who played in the yard under his mother's watchful eye. As Wiggins argued, a thing cannot undergo unlimited change. The Biblical story of Lot's wife turning into a pillar of salt is incoherent, because there is no covering sortal concept under which one can identify, first a female human being, and then a pillar of salt. There is no logical difference between Lot's wife 'turning into' a pillar of salt and being instantaneously annihilated and replaced by a pillar of salt.

A sortal concept is Aristotle's 'secondary substance'.

These contemporary arguments add to Aristotle and are not merely expositions of his theory. However, it could be argued that they are fully Aristotelian in spirit (if we ignore the point I made in my comments on your essay on the four causes: Wiggins in fact goes on to offer a theory of how unobservable structures are part of the notion of a sortal concept, which is very un-Aristotelian).

Of all Aristotle's doctrines (so far as I can think, at this moment anyway) the doctrine of primary and secondary substance, and the claim of the priority of spatio-temporal particulars is the most enduring, and is taken as the starting point for contemporary excursions into metaphysics.

All the best,

Geoffrey