Hitler is an outcome of Rousseau.

The fundamental defect of fathers, in our competitive society, is that they want their children to be a credit to them. We all feel instinctively, that our children's success reflect glory upon ourselves, while their failures make us feel shame. Unfortunately, the successes which cause us to swell with pride are often of an undesirable kind.... Neither happiness nor virtue, but worldly success, is what the average father desires for his children.

Adventurous men enjoy shipwrecks, mutinies, earthquakes, conflagrations, and all kinds of unpleasant experiences. They say to themselves, for example, 'So this is what an earthquake is like,' and it gives them pleasure to have their knowledge of the world increased by this new item.

Mathematics is only the art of saying the same thing in different words.

Most people would sooner die than think; in fact, they do so.

Science can teach us, and I think our hearts can teach us, no longer to look around for imaginary supporters, no longer to invent allies in the sky, but rather to look to our own efforts here below to make the world a fit place to live.

As soon as we abandon our own reason, and are content to rely upon authority, there is no end to our troubles.