Stuffs, and Real Kinds: More Mama, More Milk and More Mouse

Concepts, taken as items that the psyche "acquires", are highly theoretical entities. There is no way to study them empirically without committing oneself to substantial preliminary assumptions about their nature. One aim of this paper is to show how, throughout the changing variety of competing theories of concepts and categorization developed by psychologists in the last thirty years, the implicit theoretical assumption of descriptionism has never seriously been challenged. I present a nondescriptionist theory of the nature of the most basic concepts that we possess, concepts of what I will call "substances," following Aristotle. "Substances" include stuffs (gold, milk), real kinds (cat, chair) and also individuals (Mama, Bill Clinton, The Empire State Building). And yet, I argue, the category "substance" is univocal: stuffs, real kinds and individuals have something important in common. Based on this similarity, I propose, the earliest and most fundamental concepts that we have of these three sorts of things are identical in structure. The extension of "cat," like the extent of "Mama," is a natural unit in nature, a unit to which the concept cat does something like pointing, and to which it can continue to point despite large changes in the properties the thinker represents the unit as having. For example, large changes can occur in the manner in which a child identifies cats and in the selection of things the child is willing to call "cat" without affecting the extension of the child's word "cat." The difficulty, of course, and a main purpose of the essay, is to cash out the metaphor of "pointing" in this context (c.f., Putnam's "indexicality"). As I will describe substance concepts, having these does not need to depend on knowing words. On the other hand, language interacts with substance concepts in vigorous ways so as to completely transform the conceptual repertoire. I will discuss how the public language plays a crucial role both in the acquisition of substance concepts and in their completed structure.