Full Idea
It is only when beliefs are given some symbolic expression that they acquire the precision and stability that enables us to entertain them.
Gist of Idea
We can't contemplate our beliefs until we have expressed them
Source
D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.5)
Book Reference
O'Connor,D.J.: 'The Correspondence Theory of Truth' [Hutchinson 1975], p.32