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

Great minds think for themselves.

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.

All thought must, directly or indirectly, by way of certain characters, relate ultimately to intuitions, and therefore, with us, to sensibility, because in no other way can an object be given to us.

It is by his activities and not by enjoyment that man feels he is alive. In idleness we not only feel that life is fleeting, but we also feel lifeless.

Even a man's exact imitation of the song of the nightingale displeases us when we discover that it is a mimicry, and not the nightingale.

Happiness, though an indefinite concept, is the goal of all rational beings