The Individuation of Matter in Ockham's Philosophy

THE INDIVIDUATION OF MATTER IN OCKHAM'S PHILOSOPHY The problem of individuation of prime matter as it arises within Ockham's philosophical system is considered by some people to be particularly difficult given some of Ockham's views on matter. This paper will try to clarify some of the issues involved by examining them in terms of two related questions: the question of how matters combine to form wholes and the question of how whole matters can be counted . My discussion issues from some points made by M. Adams in her unpublished typescript on Ockham and from Father Weisheipl's paper "Matter in fourteenth century science": in his paper, for example, Father Weisheipl seems to imply that Ockham's view of matter is inadequate because he will not be able to provide a metaphysical criterion for the individuation of matter, while M. Adams seems to think that Ockham will also be unable to offer a consistent non-circular account of how we individuate matter. I will try to offer some, I hope, plausible ways to look at the problem of individuation of matter in Ockham's philosophy; and I will attempt to make some of the more implausible points more acceptable. There are many interesting points and puzzles raised by the debate between the Unitarians and the Pluralists over the status to be assigned to matter and form as parts of composite substances. Aquinas wants to consider prime matter as purely potential and wants to say that all the actuality which a composite substance has, is given to it by the substantial form. Because matter is purely potential Aquinas wants to consider it to be unintelligible. Pluralists like Scotus and Ockham, on the other hand, thought that matter, in order to be a part of a composite has to have some sort of actuality, though, admittedly , a sort of actuality different from the actuality of form, (for the purpose of characterizing this difference a distinction is made by Sco- 198SIMONA MASSOBRIO tus, and accepted by Ockham, between two senses of "being in act" as well as two senses of "being in potentiality"1). Similarly Scotus and Ockham will hold, against Aquinas and other Unitarians, that matter, since it has actuality, is also intelligible on its own. Also it seems that Ockham and Scotus would consider matter and form to be really distinct and this will result in the charge that they cannot account for the essential unity of composite substances of natural kinds. It will also render their claim, that the ontologically basic things in the world are composite substances, unconvincing: from their view, in fact, it would seem to follow that matter and form should be ontologically basic 2. However, all of the problems created by and connected with these views are common to Ockham and to all those who share his position: the issues connected with Ockham's views on the individuation ofmatter and related topics, on the other hand, raise problems which are peculiar to Ockham's philosophy and it is these issues which I want to discuss. Aquinas thought that matter was individuated by quantity: what made a matter "this matter" were quantitative dimentions. Scotus, on the other hand, criticized him by saying that accidents cannot individuate and hence thought that matter and form are both individuated by a "thisness." Even though Aquinas and Scotus disagree as to what 1 For Scotus there are two senses of "being in potentiality" and two senses of "being in act": (i) A thing may be the subject of the potentiality ("subjective potentiality"), or (ii) the object of the potentiality ("objective potentiality "). Complementary to the distinction between subjective and objective potentiality comes the distinction between two senses of "being in act." Act can be: (i) Act contrasted with potentiality; matter can in this first sense be in act and have an actuality of its own. (ii) Act as "something that informs something": in this second sense matter is not a being in act (only form can be), but is merely in potentiality with respect to being in act. 2 1 am not going to discuss the problems and debates which issue from the real distinction between matter and form and...