Two things fill the mind with ever-increasing wonder and awe, the more often and the more intensely the mind of thought is drawn to them: the starry heavens above me and the moral law within me... Morality is not properly the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

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.

Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.

The bad thing of war is, that it makes more evil people than it can take away.

Even philosophers will praise war as ennobling mankind, forgetting the Greek who said: 'War is bad in that it begets more evil than it kills.'

Space and time are the framework within which the mind is constrained to construct its experience of reality.

Suicide is not abominable because God prohibits it; God prohibits it because it is abominable.