Faith is not uprooted by dialectic proof; it must already be deeply shaken by other causes to be unable to withstand the shock of argument.

One cannot long remain so absorbed in contemplation of emptiness without being increasingly attracted to it. In vain one bestows on it the name of infinity; this does not change its nature. When one feels such pleasure in non-existence, one's inclination can be completely satisfied only by completely ceasing to exist.

Man is a moral being, only because he lives in society. Let all social life disappear and morality will disappear with it.

At this point, an urgent question arises: [...] Is it our duty to seek to become a thorough and complete human being, one quite sufficient unto himself; or, on the contrary, to be only a part of a whole, the organ of an organism? Briefly, is the division of labor, at the same time that it is a law of nature, also a moral rule of human conduct; and, if it has this latter character, why and in what degree?

The man whose whole activity is diverted to inner meditation becomes insensible to all his surroundings.

Each new generation is reared by its predecessor; the latter must therefore improve in order to improve its successor. The movement is circular.

Our excessive tolerance with regard to suicide is due to the fact that, since the state of mind from which it springs is a general one, we cannot condemn it without condemning ourselves; we are too saturated with it not partly to excuse it.