Obsession is the wellspring of genius and madness.

There is no greater enemy to those who would please than expectation.

Books are pleasant, but if by being over-studious we impair our health and spoil our good humour, two of the best things we have, let us give it over. I, for my part, am one of those who think no fruit derived from them can recompense so great a loss.

The man who thinks he knows does not yet know what knowing is

It needs good management to enjoy life. I enjoy it twice as much as others, for the measure of enjoyment depends on the greater or less attention that we give to it...The shorter my possession of life the deeper and fuller I must make it.

We can be knowledgeable with other men's knowledge, but we cannot be wise with other men's wisdom.

Most men are rich in borrowed sufficiency: a man may very well say a good thing, give a good answer, cite a good sentence, without at all seeing the force of either the one or the other.