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.

The schematicism by which our understanding deals with the phenomenal world ... is a skill so deeply hidden in the human soul that we shall hardly guess the secret trick that Nature here employs.

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

...as soon as we examine suicide from the standpoint of religion we immediately see it in its true light. We have been placed in this world under certain conditions and for specific purposes. But a suicide opposes the purpose of his creator; he arrives in the other world as one who has deserted his post; he must be looked upon as a rebel against God. God is our owner; we are his property; his providence works for our good.

Immaturity is the incapacity to use one's intelligence without the guidance of another.

With men, the state of nature is not a state of peace, but war.

Intuition and concepts constitute... the elements of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition without concepts, can yield knowledge.