Conquering matter is to understand it, and understanding matter is necessary to understanding the universe and ourselves: and that therefore Mendeleev's Periodic Table, which just during those weeks we were learning to unravel, was poetry.

To accuse another of having weak kidneys, lungs, or heart, is not a crime; on the contrary, saying he has a weak brain is a crime. To be considered stupid and to be told so is more painful than being called gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness, every vice, has found its defenders, its rhetoric, its ennoblement and exaltation, but stupidity hasn't.

They sensed that what had happened around them and in their presence, and in them, was irrevocable. Never again could it be cleansed; it would prove that man, the human species - we, in short - had the potential to construct an enormity of pain, and that pain is the only force created from nothing, without cost and without effort. It is enough not to see, not to listen, not to act.

Those who deny Auschwitz would be ready to remake it.

Perhaps one cannot, what is more one must not, understand what happened, because to understand [the Holocaust] is almost to justify...no normal human being will ever be able to identify with Hitler, Himmler, Goebbels, Eichmann, and endless others. This dismays us, and at the same time gives us a sense of relief, because perhaps it is desirable that their words (and also, unfortunately, their deeds) cannot be comprehensible to us. They are non-human words and deeds, really counter-human.

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.

To give a name to a thing is as gratifying as giving a name to an island, but it is also dangerous: the danger consists in one's becoming convinced that all is taken care of and that once named, the phenomenon has also been explained.