Honesty is better than any policy.

Both love of mankind, and respect for their rights are duties; the former however is only a conditional, the latter an unconditional, purely imperative duty, which he must be perfectly certain not to have transgressed who would give himself up to the secret emotions arising from benevolence.

Philosophy stands in need of a science which shall determine the possibility, principles, and extent of human knowledge à priori.

When a thoughtful human being has overcome incentives to vice and is aware of having done his bitter duty, he finds himself in a state that could be called happiness, a state of contentment and peace of mind in which virtue is its own reward.

We assume a common sense as the necessary condition of the universal communicability of our knowledge, which is presupposed in every logic and every principle of knowledge that is not one of skepticism.

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.

I feel a complete thirst for knowledge and an eager unrest to go further in it as well as satisfaction at every acquisition. There was a time when I believed that this alone could constitute the honor of mankind, and I had contempt for the ignorant rabble who know nothing.