For, after all, the foundation of our whole nature, and, therefore, of our happiness, is our physique, and the most essential factor in happiness is health, and, next in importance after health, the ability to maintain ourselves in independence and freedom from care.

Something of great importance now past is inferior to something of little importance now present, in that the latter is a reality, and related to the former as something to nothing.

Mensch kann tun was er will; er kann aber nicht wollen was er will. (One can choose what to do, but not what to want.)

Sexual passion is the cause of war and the end of peace, the basis of what is serious... and consequently the concentration of all desire

Every possession and every happiness is but lent by chance for an uncertain time, and may therefore be demanded back the next hour.

Reason deserves to be called a prophet; for in showing us the consequence and effect of our actions in the present, does it not tell us what the future will be?

I have described religion as the metaphysics of the people.