The business of philosophy is not to give rules, but to analyze the private judgments of common reason.

The possession of power inevitably spoils the free use of reason.

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.

It is precisely in knowing its limits that philosophy consists.

At some future day it will be proved, I cannot say when and where, that the human soul is, while in earth life, already in an uninterrupted communication with those living in another world.

All perception is colored by emotion.

He who has made great moral progress ceases to pray