Thinking in pictures precedes thinking in words.

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.

Human reason is by nature architectonic.

The question is not so much whether there is life on Mars as whether it will continue to be possible to live on Earth

In every department of physical science there is only so much science, properly so-called, as there is mathematics.

Freedom is independence of the compulsory will of another, and in so far as it tends to exist with the freedom of all according to a universal law, it is the one sole original inborn right belonging to every man in virtue of his humanity.

Every human being should always be treated as an end and never as a mere instrument.