Full Idea
Concepts lead us to make investigations; are the expression of our interest, and direct our interest.
Gist of Idea
Concepts direct our interests and investigations, and express those interests
Source
Ludwig Wittgenstein (Philosophical Investigations [1952], §570)
Book Reference
Wittgenstein,Ludwig: 'Philosophical Investigations', ed/tr. Anscombe,E. [Blackwell 1972], p.151
A Reaction
This presumably points to the evolutionary origin of our concept-creating capacity, though I am not sure that it defines what a concept actually is.