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.

A country is considered the more civilised the more the wisdom and efficiency of its laws hinder a weak man from becoming too weak and a powerful one too powerful.

I am constantly amazed by man's inhumanity to man.

If a writer is convinced that he is honest, then it is very difficult for him to be a bad writer.

A scientist's life, the author says, is indeed conflictual, formed by battles, defeats, and victories: but the adversary is always and only the unknown, the problem to be solved, the mystery to be clarified. It is never a matter of civil war; even though of different opinions, or of different political leanings, scientists dispute each other, they compete, but they do not battle: they are bound together by a strong alliance, by the common faith "in the validity of Maxwell's or Boltzmann's equations," and by the common acceptance of Darwinism and the molecular structure of DNA.

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.

Nothing can be said: nothing sure, nothing probable, nothing honest. Better to err through omission than through commission: better to refrain from steering the fate of others, since it is already so difficult to navigate one's own.