I'm a libertine, but it's not my specialty.

The butterfly's attractiveness derives not only from colors and symmetry: deeper motives contribute to it. We would not think them so beautiful if they did not fly, or if they flew straight and briskly like bees, or if they stung, or above all if they did not enact the perturbing mystery of metamorphosis: the latter assumes in our eyes the value of a badly decoded message, a symbol, a sign.

There is Auschwitz, and so there cannot be God.

Sooner or later in life everyone discovers that perfect happiness is unrealizable, but there are few who pause to consider the antithesis: that perfect unhappiness is equally unattainable. The obstacles preventing the realization of both these extreme states are of the same nature: they derive from our human condition which is opposed to everything infinite.

It is neither easy nor agreeable to dredge this abyss of viciousness, and yet I think it must be done, because what could be perpetrated yesterday could be attempted again tomorrow, could overwhelm us and our children. One is tempted to turn away with a grimace and close one's mind: this is a temptation one must resist. In fact, the existence of the death squads had a meaning, a message: 'We, the master race, are your destroyers, but you are no better than we are; if we so wish, and we do so wish, we can destroy not only your bodies, but also your souls, just as we have destroyed ours.

I have many times been praised for my lack of animosity towards the Germans. It's not a philosophical virtue. It's a habit of having my second reactions before the first.

He was a physicist, more precisely an astrophysicist, diligent and eager but without illusions: the Truth lay beyond, inaccessible to our telescopes, accessible to the initiates. This was a long road which he was traveling with effort, wonderment, and profound joy. Physics was prose: elegant gymnastics for the mind, mirror of Creation, the key to man's dominion over the planet; but what is the stature of Creation, of man and the planet? His road was long and he had barely started up it, but I was his disciple: did I want to follow him?