Two things awe me most, the starry sky above me and the moral law within me.

It is by his activities and not by enjoyment that man feels he is alive. In idleness we not only feel that life is fleeting, but we also feel lifeless.

Reason should investigate its own parameters before declaring its omniscience.

Our knowledge springs from two fundamental sources of the mind; the first is the capacity of receiving representations (receptivity for impressions), the second is the power of knowing an object through these representations (spontaneity [in the production] of concepts).

If we knew that god exists, such knowledge would make morality impossible. For, if we acted morally from fear or fright, or confident of a reward, then this would not be moral. It would be enlightened selfishness.

We are not rich by what we possess but by what we can do without.

How then is perfection to be sought? Wherein lies our hope? In education, and in nothing else.