Tolstoy On How To Live

"When Levin thought about what he was and what he lived for, he found no answer and fell into despair; but when he stopped asking himself about it, he seemed to know what he was and what he lived for, because he acted and lived firmly and definitely. . .

Reasoning led him into doubt and kept him from seeing what he should and should not do. Yet when he did not think, but lived, he constantly felt in his soul the presence of an infallible judge who decided which of two possible actions was better and which was worse; and whenever he did not act as he should, he felt it at once.

So he lived, not knowing and not seeing any possibility of knowing what he was and why he was living in the world, tormented by this ignorance to such a degree that he feared suicide, and at the same time firmly laying down his own particular, definite path in life."

- Anna Karenina (Pevear & Volokhonsky translation), pgs. 820 - 822.