"And who is and should be a pessimist? He who is mature for death and is in no condition to love life, just as the optimist cannot turn away from it. If he does not realize that he will live on in his children, his procreation loses its horrible character; but if he does realize it, he will recoil in horror from it, just like Humboldt when he noticed that the torments that another being must endure for perhaps eighty years are too high a price to pay for a few minutes of pleasure, and will consider the procreation of children, and rightly so, as a crime."
January 1, 1970
https://en.wikiquote.org/wiki/Philosophical_pessimism