Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me and the moral law within me. I do not seek or conjecture either of them as if they were veiled obscurities or extravagances beyond the horizon of my vision; I see them before me and connect them immediately with the consciousness of my existence.

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

The greatest problem for the human species, the solution of which nature compels him to seek, is that of attaining a civil society which can administer justice universally.

The sum total of all possible knowledge of God is not possible for a human being, not even through a true revelation. But it is one of the worthiest inquiries to see how far our reason can go in the knowledge of God.

Life is the faculty of spontaneous activity, the awareness that we have powers.

In all judgements by which we describe anything as beautiful, we allow no one to be of another opinion.

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