Full Idea
Definitions characterise things that are inherent in the concept, but we are concerned with how humans get a handle on the concept - to understand it and function in terms of it.
Gist of Idea
Definitions give the essence of a concept, but metaphors are how we use them
Source
G Lakoff / M Johnson (Metaphors We Live By [1980], 19)
A Reaction
Their thesis about metaphorical thought is particularly persuasive if it concerns mental techniques we use in order to grasp and manipulate concepts (for example, the way we think about and discuss arguments). Metaphor is a tool of coherence.
Book Reference
Lakoff,G/Johnson,M: 'Metaphors We Live By' [Chicago 2003], p.116