The ideal of the supreme being is nothing but a regulative principle of reason which directs us to look upon all connection in the world as if it originated from an all-sufficient necessary cause.

The infinitude of creation is great enough to make a world, or a Milky Way of worlds, look in comparison with it what a flower or an insect does in comparison with the Earth.

Nature does nothing in vain, and in the use of means to her goals she is not prodigal.

A single line in the Bible has consoled me more than all the books I ever read besides.

Have the courage to use your own reason- That is the motto of enlightenment. "Foundations of the Metaphysics of Morals" (1785)

A man who has tasted with profound enjoyment the pleasure of agreeable society will eat with a greater appetite than he who rode horseback for two hours. An amusing lecture is as useful for health as the exercise of the body.

I assert that, in any particular natural science, one encounters genuine scientific substance only to the extent that mathematics is present.