It is in our own mind and not in exterior objects that we perceive most things; fools know scarcely anything because they are empty, and their heart is narrow; but great souls find in themselves a number of exterior things; they have no need to read or travel or to listen or to work to discover the highest truths; they have only to delve into themselves and search, if we may say so, their own thoughts.

p. 186. - Reflections and Maxims (1746)