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

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

Thinking in pictures precedes thinking in words.

Human reason has this peculiar fate that in one species of its knowledge it is burdened by questions which, as prescribed by the very nature of reason itself, it is not able to ignore, but which, as transcending all its powers, it is also not able to answer.

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.

We can judge the heart of a man by his treatment of animals.

Patience is the strength of the weak, impatience is the weakness of the strong.