Full Idea
We typically conceptualise the nonphysical in terms of the physical - that is, we conceptualise the less clearly delineated in terms of the more clearly dilineated.
Gist of Idea
We usually conceptualise vague nonphysical things in terms of more precise physical things
Source
G Lakoff / M Johnson (Metaphors We Live By [1980], 12)
A Reaction
They sugggest 'in the kitchen' and 'in love' as instances. The authors demonstrate how this tendency runs much more deeply (see what I did there!) than you might expect.
Book Reference
Lakoff,G/Johnson,M: 'Metaphors We Live By' [Chicago 2003], p.59