Experience is a good teacher, but her fees are very high.

Civilization is being poisoned by its own waste products.

The whole of nature, as has been said, is a conjugation of the verb to eat, in the active and in the passive.

If the universe is running down like a clock, the clock must have been wound up at a date which we could name if we knew it. The world, if it is to have an end in time, must have had a beginning in time.

The statistics of suicide show that, for non-combatants at least, life is more interesting in war than in peace.

My dear, we live in an age of transition.

Philosophy means thinking things out for oneself. Ultimately, there can be only one true philosophy, since reason is one and we all live in the same world.