If man makes himself a worm he must not complain when he is trodden on.

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.

A lie is the abandonment and, as it were, the annihilation of the dignity by man.

Two things fill the mind with ever new and increasing admiration and awe, the oftener and more steadily we reflect on them: the starry heavens above and the moral law within.

Freedom is the alone unoriginated birthright of man, and belongs to him by force of his humanity.

Human beings are never to be treated as a means but always as ends.

Two things strike me dumb: the infinite starry heavens, and the sense of right and wrong in man.