It is not God's will merely that we should be happy, but that we should make ourselves happy
By a lie, a man... annihilates his dignity as a man.
Time is not an empirical concept. For neither co-existence nor succession would be perceived by us, if the representation of time did not exist as a foundation a priori.
All perception is colored by emotion.
Give a man everything he wants and at that moment everything is not everything
The instruction of children should aim gradually to combine knowing and doing. Among all sciences mathematics seems to be the only one of a kind to satisfy this aim most completely.