To: Plinio C.
From: Geoffrey Klempner
Subject: Aristotle on primary and secondary substances
Date: 22nd October 2009 11:38

Dear Plinio,

Thank you for your email of 14 October with your essay for the University of London BA module, Greek Philosophy: Aristotle, in response to the question, 'What according to the Categories is the relation between primary and secondary substances?'

Regarding a short book on Rawls: my recommendation would be to avoid introductions for students, and look at the original book reviews of his 'Theory of Justice', and also book reviews of longer studies of Rawls. That way, you will get a much better insight into the 'state of the art' regarding discussions of Rawls' work, and also gain extra ammunition with which to impress an examiner. Obviously, this advice applies more generally: as a rule my best students spend time researching JSTOR, or the articles available at Questia.

You have written a very good essay. With a question like this, you need to ask subsidiary questions which raise possible criticisms, and this you have done. However, bearing in mind the point I made above, some indication that you have looked at contemporary/ scholarly discussions of the topic in question will get those extra marks. (E.g. in an exam, you would say, 'Irwin makes the point that...'.)

One contemporary philosopher whose work is especially relevant to this topic is David Wiggins. In his monograph, 'Identity and Spatio-Temporal Continuity', and also in his later expanded work, 'Sameness and Substance' he provides compelling arguments based on the logic of identity statements for making the kinds of distinction that Aristotle makes: Primary substances are spatio-temporal particulars, whose identity over time depends on tracking the object in question under a sortal concept (Aristotelian secondary substance).

The background to Wiggins is Strawson's essay 'Individuals: an essay in descriptive metaphysics' which makes the case for spatio-temporal particulars as being 'basic' in our 'conceptual scheme'. (Indeed, Strawson describes Aristotle as one of the forerunners of descriptive metaphysics, by contrast with 'revisionary metaphysicians' such as Berkeley or Leibniz.) Since Wiggins, and also the important work of Putnam and Kripke, the idea that there are 'natural kinds' and that we can draw a meaningful, coherent distinction between 'accidental' properties made a comeback, after a long period where the very idea of 'essential' properties was frowned upon -- a legacy from the hostility to Scholasticism which goes back to the empiricists (Ayer is an example of a philosopher who has expressed scepticism on this point.)

Yet it is also important to remember that Aristotle intended his distinctions to do more than merely logical/ conceptual work: they link in to his account of explanation, as a radical alternative to the notion that objects (like primary substances) have a deep structure, an idea Aristotle was perfectly familiar with from the theories of the Greek atomists -- which he roundly rejected.

You make two substantial points that I would like to comment on. The first concerns the statement 'Socrates is a biped'. I agree with you that 'Socrates is a biped animal' is a perfectly acceptable reading (and indeed the reading that one would normally intend). However, there is an obvious problem in that if we remove one or both of Socrates' legs, he is still a 'biped animal'. Being a biped animal is essential to Socrates, yet not in the sense that Socrates is unable to survive the removal of his legs. On the other hand, 'Socrates is a cordate' or 'Socrates is a renate' describe attributes which cannot be removed without causing the death of Socrates.

(There is also a possible reading which would apply in a universe where human beings have varieties of numbers of legs -- like differing amounts of hair -- and no particular number is more characteristic of a human being than another number. In the actual universe, if I remarked, 'Socrates is biped', there is a context in which this would be construed as a remark about the actual number of legs which Socrates has.)

The second point, which is perhaps more important, concerns the ontological status of primary and secondary substances. Secondary substances, for Aristotle, have if anything a far greater importance than they would for a contemporary 'essentialist' because of their connection with Formal explanation, as indicated above. Natural kinds are real, not just classifications in our head, and moreover they are what ultimately explain the powers of primary substances. Also, if we apply the test of whether X can exist without Y, or Y without X, we get the result that primary substances like Socrates and secondary substances like Man are 'equal' from an ontological standpoint. Neither can be without the other.

Yet, is that the only criterion? Isn't it also true that our mode of access to natural kinds such as Man is necessarily via primary substances. In Aristotelian science, we are 'given' the primary substances, an individual man or plant, and discover the natural kinds, their species and genera.

What this shows, however, is that in order to make the case for the primacy of primary substances, Aristotle would need to introduce an epistemological element; as you show, drawing the logical distinctions which he does is not sufficient.

All the best,

Geoffrey