Man's restlessness makes him strive.

Everything is simpler than you think and at the same time more complex than you imagine

There are situations in which hope and fear run together, in which they mutually destroy one another and lose themselves in dull indifference.

Of all thieves, fools are the worst; they rob you of time and temper.

All truly wise thoughts have been thought already thousands of times; but to make them truly ours, we must think them over again honestly, until they take root in our personal experience.

The most damaging prejudice consists of banning any kind of investigation of nature.

Superstition is part of the poetry of life.