It is shown that a set-theoretical (in particular, Fregean) definition of concepts implies that whatever is claimed using the term 'concept' can be claimed using the term 'class' and that the only remedy consists in construing concepts as a kind of abstract procedure.
It is shown that a set-theoretical (in particular, Fregean) definition of concepts implies that whatever is claimed using the term 'concept' can be claimed using the term 'class' and that the only remedy consists in construing concepts as a kind of abstract procedure. (en)