It is most important to allow the brain the full measure of sleep which is required to restore it; for sleep is to a man's whole nature what winding up is to a clock.
A man of intellect is like an artist who gives a concert without any help from anyone else, playing on a single instrument--a piano, say, which is a little orchestra in itself. Such a man is a little world in himself; and the effect produced by various instruments together, he produces single-handed, in the unity of his own consciousness. Like the piano, he has no place in a symphony; he is a soloist and performs by himself--in soli tude, it may be; or if in the company with other instruments, only as principal; or for setting the tone, as in singing.
In early youth, as we contemplate our coming life, we are like children in a theatre before the curtain is raised, sitting there in high spirits and eagerly waiting for the play to begin.
there are very few who can think, but every man wants to have an opinion; and what remains but to take it ready-made from others, instead of forming opinions for himself?
One can never read too little of bad, or too much of good books: bad books are intellectual poison; they destroy the mind. In order to read what is good one must make it a condition never to read what is bad; for life is short, and both time and strength limited.
The fourfold root of the principle of sufficent reason is "Anything perceived has a cause. All conclusions have premises. All effects have causes. All actions have motives.
What a man can do and suffer is unknown to himself till some occasion presents itself which draws out the hidden power. Just as one sees not in the water of an unruffled pond the fury and roar with which it can dash down a steep rock without injury to itself, or how high it is capable of rising; or as little as one can suspect the latent heat in ice-cold water.
If children were brought into the world by an act of pure reason alone, would the human race continue to exist? Would not a man rather have so much sympathy with the coming generation as to spare it the burden of existence, or at any rate not take it upon himself to impose that burden upon it in cold blood?