The Nature of Scientific Explanation

Lecture Three. The Principle of Substance

31 Lecture Three The Principle of Substance The thesis to be advanced in this lecture is that Aristotle’s doctrine of substance is as relevant today as it was when it was first propounded. It must be acknowledged at the outset that ideas have a life of their own, and this is no less true of certain key Aristotelian notions. Aristotle becomes more sophisticated in the commentaries of the Scholastics and still more sophisticated in the twentieth century. Indeed, some of the best contemporary work in philosophy is nothing other than the creative appropriation of the classical past and its medieval commentators. The ancients no less than we were acute in observation, precise in making distinctions, and careful in drawing implications. Where the problems haven’t changed, good answers elicit perennial appreciation ; good solutions require acknowledgment. Of course, this view is not shared by all. Reinhardt Grossman , in his “attempt to give a complete and accurate list of the categories of the world,” writes, “The nineteenth century sees the final destruction of the Aristotelian ontology. Not just one, but several new categories appear on the ontological stage: relations, 32 Basic Principles structures, classes, and facts.”1 It is easy to show that Grossman is wrong: that Aristotle’s basic insights remain intact, and that his so-called new categories are ancient ones, indeed. Aristotle employs the notion of “substance” to account for a multiplicity of phenomena. Unless otherwise indicated, “substance ” will be employed here in the Aristotelian sense of “second substance,” as contrasted to “supposit” or “existent.” Depending upon the insight to be conveyed, second substance may also be called “essence” or “nature.” The distinction between substances and accidents enables Aristotle to distinguish between changes that merely modify and changes that remove a thing from its class. Furthermore, in the order of explanation, it provides an account of the reception and the conferral of action and an account of how a multiplicity of qualities can exist in the same subject. Importantly, it suggests an analogue for inquiry into “social” as opposed to “natural” processes and structures. These several theses are but aspects of a unified theory of being and knowing. They are defended neither in isolation from their ontological roots nor in ignorance of their implications, yet not all that is presupposed here can be defended within the brief span of this presentation. While the vantage point that governs this inquiry is only one of many strands discernable in the Western intellectual tapestry, it is taken as one required by both ordinary and scientific inquiry. To formulate questions in a certain way is to invite certain answers. If we ask the twin questions (1) “How can the individual in the order of activity change and yet remain the same individual?” and (2) “What does it mean to achieve scientific knowledge?” both questions inevitably lead to the invocation of ontological structures recognized in the Aristotelian corpus. To tackle the latter question first is a decidedly 1. Reinhardt Grossman, The Categorial Structure of the World (Bloomington: Indiana University Press, 1983), xvi. 33 Lecture Three: Substance un-Aristotelian move, but for the purposes at hand, my infidelity may be justified. Let us speak first about the nature of knowledge, particularly scientific knowledge. If one assumes that the aim of science, as we have previously suggested, is to find the structures or states from which the phenomena of nature flow, then scientific knowledge consists of two main types of information. As Rom Harré has argued, scientific knowledge consists (1) in knowledge of the internal structures of persisting things and materials and (2) in the knowledge of the statistics of events, of the behavior of such things and materials, wherein one discerns patterns among these events through certain types of change, but not through other kinds.2 Emphasis is placed on structures and their persistence. The recognition of such units and their differentiation is the recognition of natural kinds. The chemical analysis of a material, the genes inherited from a parent, the structure of a crystal, the electronic configuration of an atom, point to real structures and to real essences. In them reside the powers of generation and production through the operation of which the flux of events results. That is, a scientific exploration consists essentially in accounting for the second type of information in terms of the first. In a scientific exploration, we show how the patterns discerned among events are produced...