Scotistic Hylomorphism and the Problem of Homonymy

Chapter 10 Scotistic Hylomorphism and the Problem of Homonymy

In this final chapter I will argue for a thesis which I believe to be Scotus’s but which I also believe to be true. I will argue that a hylomorphist should hold that a material substance can be composed of material substances, that he should be what I call a Scotistic pluralist. The plan for the chapter is as follows: I will review some of the features that make Scotistic hylomorphism Scotistic, and contrast these with certain features of different versions of hylomorphism. I will move on to pose a serious problem with hylomorphism, first raised, as far as I know, by J.L. Ackrill.1 Then I will sketch the ways in which different versions of hylomorphism can respond to Ackrill’s problem, and argue that Scotistic hylomorphism has the best response. i Scotistic Hylomorphism Among Other Varieties

Take it for granted, that for any material substance, there is something or some things that it is made out of. Let us say, following an ordinary way of speaking (at least in metaphysics), that what a substance is made out of constitutes that substance, and (following an older way of speaking) let’s call that which constitutes a substance the matter of that substance. All hylomorphists agree that a substance is not identical with that which constitutes it, is not identical with its matter. They argue that the matter of any material substance is formed, structured, organized, in some way and that an expla- nation of the form, structure, or organization of the matter of a substance must involve some ontological commitment to something in addition to the matter. Hylomorphists call this additional something, form. A material substance turns out to be, on nearly every hylomorphic theory, some sort of composite of matter and form.2

1 J.L. Ackrill, “Aristotle’s Definitions of ‘Psuche’,” Proceedings of the Aristotelian Society 73 (1972– 1973), pp. 119–133. Ackrill’s problem is concisely expressed by Christopher Shields, “The Fundamental Problem about Hylomorphism,” Stanford Encyclopedia of Philosophy 2010, http://plato.stanford.edu/entries/aristotle-psychology/suppl1.html. 2 I know of one exception: Mark Johnston, “Hylomorphism,” Journal of Philosophy 103:12 (2006, pp. 692–698. Johnston denies that forms are parts of the objects whose forms they are.

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On older versions of hylomorphism, such as Scotus’s, a division of forms into substantial and accidental is put to heavy use. A substantial form is sup- posed to be the sort of form that structures matter and makes a substance, while an accidental form structures a substance in a certain way, characteriz- ing it but not changing its essence or nature. For the purposes of this chapter I am concerned exclusively with substantial form. Perhaps the most significant disagreement between hylomorphists is the one I will be focusing on here. It concerns whether or not the matter of a substance, s, can itself be one or more substances while it is the matter of s, which by transitivity of parthood (on the assumption that matter is a part of the substance whose matter it is) amounts to a disagreement about whether or not a substance can have one or more substances as parts. Aquinas held that for every substance you count you must count no more or less than one substantial form. (Following my earlier usage, I will call him and others who agree with him unitarians about substantial form.) Unitarians therefore deny that a substance can be composed of substances. Scotus and Ockham held that one substance can have more than one substantial form. (We will continue to call them pluralists about substantial form.) Pluralists therefore affirm that a substance can be composed of substances. But there are two very different kinds of pluralism, what I have called (a little unimagina- tively) standard pluralism and Scotistic pluralism. In order to understand the differences between these kinds of pluralisms, recall another term of art from earlier chapters: a part-substance is a substance that is a part of a substance. Pluralists think there are part-substances; unitarians do not. For both standard and Scotistic pluralists, a whole substance can be composed of several part- substances, and one part-substance can be composed of several part-substances. But, to speak loosely, whereas the standard pluralist will deny that integral parts like hands, eyes, and hearts can be individual substances while they compose a substance, the Scotistic pluralist affirms this. More strictly, for Standard Pluralists,

[Standard Pluralism] For any substance, w, part-substance of w, x, and part-substance of w, y, if x ≠ y then either x is a part-substance of y or y is a part-substance of x.

But for Scotistic pluralists,

[Scotistic Pluralism] For some substance, w, part-substance of w, x, and part-substance of w, y, such that x ≠ y, x is not a part-substance of y and y is not a part-substance of x.