Our knowledge springs from two fundamental sources of the mind; the first is the capacity of receiving representations (receptivity for impressions), the second is the power of knowing an object through these representations (spontaneity [in the production] of concepts).

The instruction of children should aim gradually to combine knowing and doing. Among all sciences mathematics seems to be the only one of a kind to satisfy this aim most completely.

Act that your principle of action might safely be made a law for the whole world.

The wish to talk to God is absurd. We cannot talk to one we cannot comprehend — and we cannot comprehend God; we can only believe in Him.

Look closely. The beautiful may be small.

Morality is not properly the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

The business of philosophy is not to give rules, but to analyze the private judgments of common reason.