Concepts *

a also take a deep interest in questions about conceptual structure. It's just that the structure in question is supposed to be the structure of abstract entities. See, e.g., Peacocke (1992) and Bealer (1982). 7 As the examples here indicate, the Classical Theory (and indeed all the theories we will be discussing) is, in the first instance, a theory about the nature of concepts that correspond to words in natural language—what are called lexical concepts. This is because theorists interested in concepts assume that the representations corresponding to natural language phrases or sentences are structured. 8 The motivation for the Classical Theory is by no means limited to these virtues. For example, another influential point in favor of this theory is its ability to explain our intuitions that certain statements or arguments are valid even though, on the face of it, they fail to express logical truths, e.g., "John is a bachelor, so John is unmarried" (see, e.g., Katz 1972).