One should respect an honest person even if he expresses opinions differing from one's own.

Nature hides her secrets because of her essential loftiness, but not by means of ruse.

The most beautiful thing we can experience is the mysterious. It is the source of all true art and science.

Regarding sex education: no secrets!

Lasting harmony with a woman (was) an undertaking in which I twice failed rather disgracefully.

All our thinking is of this nature, a free play with concepts.

The horizon of many people is a circle with a radius of zero. They call this their point of view.