That human life must be some kind of mistake is sufficiently proved by the simple observation that man is a compound of needs which are hard to satisfy; that their satisfaction achieves nothing but a painless condition in which he is only given over to boredom . . .
The ordinary method of education is to imprint ideas and opinions, in the strict sense of the word, prejudices, on the mind of the child, before it has had any but a very few particular observations. It is thus that he afterwards comes to view the world and gather experience through the medium of those ready-made ideas, rather than to let his ideas be formed for him out of his own experience of life, as they ought to be.
Optimism is not only a false but also a pernicious doctrine, for it presents life as a desirable state and man's happiness as its aim and object. Starting from this, everyone then believes he has the most legitimate claim to happiness and enjoyment. If, as usually happens, these do not fall to his lot, he believes that he suffers an injustice, in fact that he misses the whole point of his existence.
Every generation, no matter how paltry its character, thinks itself much wiser than the one immediately preceding it, let alone those that are more remote.
For an act to be moral the intention must be based on compassion, not duty. We do something because we want to do it, because we feel we have to do it, not because we ought to do it. And even if our efforts fail - or we never even get to implement them - we are still moral because our motivation was based on compassion.
Nothing shocks our moral feelings so deeply as cruelty does. We can forgive every other crime, but not cruelty. The reason for this is that it is the very opposite of compassion.