All intelligent thoughts have already been thought; what is necessary is only to try to think them again.

Intelligent people tend to have less friends than the average person. The smarter you are, the more selective you become.

I've always felt that a person's intelligence is directly reflected by the number of conflicting points of view he can entertain simultaneously on the same topic.

What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.

To criticize is to appreciate, to appropriate, to take intellectual possession, to establish in fine a relation with the criticized thing and to make it one's own.

The first method of estimating the intelligence of a ruler is to look at the men he has around him.

No power and no treasure can outweigh the extension of our knowledge.

Opinion is the medium between knowledge and ignorance.

The possession of knowledge does not kill the sense of wonder and mystery. There is always more mystery.

Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and unbearable pity for the suffering of mankind.

For beautiful eyes, look for the good in others; for beautiful lips, speak only words of kindness; and for poise, walk with the knowledge that you are never alone.

Knowing your own darkness is the best method for dealing with the darknesses of other people.

Teach the ignorant as much as you can; society is culpable in not providing a free education for all and it must answer for the night which it produces. If the soul is left in darkness sins will be committed. The guilty one is not he who commits the sin, but he who causes the darkness.

Knowledge rests not upon truth alone, but upon error also.

He who has so little knowledge of human natures as to seek happiness by changing anything but his own disposition will waste his life in fruitless efforts.

Two percent of the people think; three percent of the people think they think; and ninety-five percent of the people would rather die than think.

I like thinking big. If you’re going to be thinking anything, you might as well think big.

Appearances to the mind are of four kinds. Things either are what they appear to be; or they neither are, nor appear to be; or they are, and do not appear to be; or they are not, and yet appear to be. Rightly to aim in all these cases is the wise man’s task.

To make a contented slave it is necessary to make a thoughtless one. It is necessary to darken the moral and mental vision and, as far as possible, to annihilate the power of reason.

The positive thinker see the invisible, feels the intangible, and achieve the impossible.

All truly great thoughts are conceived by walking.

Factual evidence can never “prove” a hypothesis; it can only fail to disprove it, which is what we generally mean when we say, somewhat inexactly, that the hypothesis is “confirmed” by experience.

I have always believed, and I still believe, that whatever good or bad fortune may come our way we can always give it meaning and transform it into something of value.