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

Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.

Prudence reproaches; conscience accuses.

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.

We find that the more a cultivated reason devotes itself to the aim of enjoying life and happiness, the further does man get away from true contentment.

Thinking in pictures precedes thinking in words.

Nature, when left to universal laws, tends to produce regularity out of chaos.