This chapter will define concept possession, and distinguish it from the stronger notions of understanding and mastery. To possess a concept, we will argue, is to have conceived it and remain capable of conceiving it. We will show that nominalist and information-semantic definitions of concept possession are wide of the mark, while recognition, knowledge, and inferentialist theories are too strong.

POSSESSING CONCEPTS

Fodor has remarked that “[i]t's a general truth that if you know what an X is, then you also know what it is to have an X,” and that this applies to concepts in particular (1998a: 2). There are many senses of “have” for which Fodor's generalization fails. A child may know what a baby is without yet knowing what it is to have a baby, and may know what a woman is without yet knowing what it is to have a woman. I believe that the having of concepts is a less obvious exception. I have defined concepts as parts of thoughts, but that does not tell us what it is to have a concept.

“Having” a belief is the same as believing the belief, and “having” a thought is the same as thinking it. To “have” an idea is to conceive it. Despite this pattern, having a concept, as this phrase is commonly used, must be distinguished from conceiving a concept. We have countless concepts that we are not currently conceiving. I have had the concept of neutrons since grade school.