Gauss replied, when asked how soon he expected to reach certain mathematical conclusions, that he had them long ago, all he was worrying about was how to reach them!

Social evolution may be the result of intention, but it rarely, if ever, produces the result intended.

Sometimes the more measurable drives out the most important.

Human diversity makes tolerance more than a virtue; it makes it a requirement for survival.

... men as a rule are more preoccupied with the dangers that threaten their life than interested in the biological forces on which they depend for a constructive existence.

The very process of living is a continual interplay between the individual and his environment, often taking the form of a struggle resulting in injury or disease.

As long as mankind is made up of independent individuals with free will, there cannot be any social status quo. Men will develop new urges, and these will give rise to new problems, which will require ever new solutions. Human life implies adventure, and there is no adventure without struggles and dangers.