". . . judiciously show a cat milk, if you wish her to thirst for it. Judiciously show a dog his natural prey, if you wish him to bring it down one day."

Prejudices, it is well known, are most difficult to eradicate from the heart whose soil has never been loosened or fertilised by education: they grow there, firm as weeds among stones.

No mockery in this world ever sounds to me so hollow as that of being told to cultivate happiness. What does such advice mean? Happiness is not a potato.

"'O brothers," I said, "who through a hundred thousand perils have reached the west, to this so little vigil of our senses that remains, do not choose to deny the experience of [what lies] behind the sun, of the world without human beings. Consider your seed [the race you spring from]: you were not made to live like brutes, but to follow virtue and knowledge.'"

Inferno
(Canto 26, lines 112-120)

In historical events great men—so-called—are but labels serving to give a name to the event, and like labels they have the least possible connection with the event itself. Every action of theirs, that seems to them an act of their own free will, is in an historical sense not free at all, but in bondage to the whole course of previous history, and predestined from all eternity.

War and Peace

Pure and complete sorrow is as impossible as pure and complete joy.

--War and Peace
Book XV, chapter 1

At the approach of danger there are always two voices that speak with equal force in the heart of man: one very reasonably tells the man to consider the nature of the danger and the means of avoiding it; the other even more reasonable says that it is too painful and harassing to think of the danger, since it is not a man's power to provide for everything and escape from the general march of events; and that it is therefore better to turn aside from the painful subject till it has come, and to think of what is pleasant. In solitude a man generally yields to the first voice; in society to the second.

--War and Peace
Book X, chapter 17

A Frenchman is self-assured because he regards himself personally, both in mind and body, as irresistibly attractive to men and women. An Englishman is self-assured, as being a citizen of the best-organized state in the world, and therefore as an Englishman always knows what he should do and knows that all he does as an Englishman is undoubtedly correct. An Italian is self-assured because he is excitable and easily forgets himself and other people. A Russian is self-assured just because he knows nothing and does not want to know anything, since he does not believe that anything can be known. The German's self-assurance is worst of all, stronger and more repulsive than any other, because he imagines that he knows the truth--science--which he himself has invented but which is for him the absolute truth.

--War and Peace
Book IX, chapter 10

He had the unlucky capacity many men, especially Russians, have of seeing and believing in the possibility of goodness and truth, but of seeing the evil and falsehood of life too clearly to be able to take any serious part in life. Every sphere of activity was, in his eyes, linked with evil and deception

--Book VIII, chapter 1

Fruit and berries on strange planets either make you live or make you die. Therefore the point at which to start toying with them is when you're going to die if you don't. That way you stay ahead. The secret to healthy hitchhiking is to eat junk food.
--Ford Prefect