Abstract
After some general remarks about the contemporary debate on concepts and about the justification of the so-called definition question, I try to participate in this debate by criticizing what I take to be an instructive approach to concepts and concept possession, viz. Hans-Johann Glock's proposal to view concepts as rules or principles rather than abilities. I address his attempt to distinguish between sorting and classifying, his objections to the idea that concepts are abilities and his contention that thoughts and concepts are to be regarded as the content of thinking. I advocate a deflationary approach to concepts and try to raise doubts about the claim that thoughts have a language-independent structure.
Saporiti, Katia