Full Idea
There can be no more to a concept than is determined by a correct account of what it is to possess that concept.
Gist of Idea
A concept is just what it is to possess that concept
Source
Christopher Peacocke (A Study of Concepts [1992], 3.2)
Book Reference
Peacocke,Christopher: 'A Study of Concepts' [MIT 1999], p.71
A Reaction
He calls this the Principle of Dependence. An odd idea, if you compare 'there is no more to a book than its possession conditions'. If the principle is right, I struggle with the proposal that a philosopher might demonstrate such a principle.