An error is the more dangerous in proportion to the degree of truth which it contains.
Look twice, if what you want is a just conception; look once, if what you want is a sense of beauty.
A man only understands what is akin to something already existing in himself.
Common sense is the measure of the possible; it is composed of experience and prevision; it is calculation applied to life.
The wealth of each mind is proportioned to the number and to the precision of its categories and its points of view.