Two things awe me most, the starry sky above me and the moral law within me.

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.

cruelty to animals is contrary to man's duty to himself, because it deadens in him the feeling of sympathy for their sufferings, and thus a natural tendency that is very useful to morality in relation to other human beings is weakened.

We find that the more a cultivated reason devotes itself to the aim of enjoying life and happiness, the further does man get away from true contentment.

Three things tell a man: his eyes, his friends and his favorite quotes

A categorical imperative would be one which represented an action as objectively necessary in itself, without reference to any other purpose.

The sceptics, a kind of nomads, despising all settled culture of the land, broke up from time to time all civil society. Fortunately their number was small, and they could not prevent the old settlers from returning to cultivate the ground afresh, though without any fixed plan or agreement.