Act only according to that maxim whereby you can at the same time will that it should become a universal law.

Dare to know! Have the courage to use your own intelligence!

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.

It is difficult for the isolated individual to work himself out of the immaturity which has become almost natural for him.

Natural science physics contains in itself synthetical judgments a priori, as principles. ... Space then is a necessary representation a priori, which serves for the foundation of all external intuitions.

Maturity is having the courage to use one's own intelligence!

Great minds think for themselves.