The application of algebra to geometry... far more than any of his metaphysical speculations, has immortalized the name of Descartes, and constitutes the greatest single step ever made in the progress of the exact sciences.

First then, we find that when we regard ideas from a nominalistic, individualistic, sensualistic way, the simplest facts of mind become utterly meaningless. That one idea should resemble another or influence another, or that one state of mind should so much as be thought of in another is, from that standpoint, sheer nonsense.

Mucius might have accomplished something more successful in that camp, but never anything more brave.

Maybe somewhere in some other galaxy there is a super-intelligence so colossal that from our point of view it would be a god. But it cannot have been the sort of God that we need to explain the origin of the universe, because it cannot have been there that early.

To-day the Enlightenment ideal has been changed into a reality; not only in legislation, which is the mere framework of public life, but in the heart of every individual, whatever his ideas may be, and even if he be a reactionary in his ideas, that is to say, even when he attacks and castigates institutions by which those rights are sanctioned.... The sovereignty of the unqualified individual, of the human being as such, generically, has now passed from being a juridical idea or ideal to be a psychological state inherent in the average man. And note this, that when what was before an ideal becomes a component part of reality, it inevitably ceases to be an ideal. The prestige and the magic that are attributes of the ideal are volatilised.

Psychologists have hitherto failed to realize that imagination is a necessary ingredient of perception itself.

I must write it all out, at any cost. Writing is thinking. It is more than living, for it is being conscious of living.

No matter how honest scientists think they are, they are still influenced by various unconscious assumptions that prevent them from attaining true objectivity. Expressed in a sentence, Fort's principle goes something like this: People with a psychological need to believe in marvels are no more prejudiced and gullible than people with a psychological need not to believe in marvels.

Every man has his own circle composed of trees, animals, men, ideas, and he is in duty bound to save this circle. He, and no one else. If he does not save it, he cannot be saved. These are the labors each man is given and is in duty bound to complete before he dies. He may not otherwise be saved. For his own soul is scattered and enslaved in these things about him, in trees, in animals, in men, in ideas, and it is his own soul he saves by completing these labors.

Religions, which condemn the pleasures of sense, drive men to seek the pleasures of power. Throughout history power has been the vice of the ascetic.

Man cannot do without beauty, and this is what our era pretends to want to disregard. It steels itself to attain the absolute and authority; it wants to transfigure the world before having exhausted it, to set it to rights before having understood it. Whatever it may say, our era is deserting this world.

Eventually, I believe, current attempts to understand the mind by analogy with man-made computers that can perform superbly some of the same external tasks as conscious beings will be recognized as a gigantic waste of time.

So that it will be found that the fundamental fault in the character of women is that they have no "sense of justice ." This arises from their deficiency in the power of reasoning already referred to, and reflection, but is also partly due to the fact that Nature has not destined them, as the weaker sex, to be dependent on strength but on cunning; this is why they are instinctively crafty, and have an ineradicable tendency to lie.

He laid it down as a maxim, that monarchy was the basis of all good government and the nearer to monarchy any government approached, the more perfect it was, and vice versa; and he certainly in his wildest moments, never had so far forgotten the nature of government, as to argue that we ought to wish for a constitution that we could alter at pleasure, and change like a dirty shirt. He was by no means anxious for a monarchy with a dash of republicanism to correct it. But the French constitution was the exact opposite of the English in every thing, and nothing could be so dangerous as to set it up to the view of the English, to mislead and debauch their minds.

Without consciousness the mind-body problem would be much less interesting. With consciousness it seems hopeless.

Lost time was like a run in a stocking. It always got worse.

There are circumstances in which even the least energetic of mankind learn to behave with vigour and decision; and the most cautious forget their prudence and embrace foolhardy resolutions.

What the learned world tends to offer is one second-hand scrap of information illustrating ideas derived from another second-hand scrap of information. The second-handedness of the learned world is the secret of its mediocrity.

Art is a human activity consisting in this, that one consciously, by means of certain external symbols, conveys to others the feelings one has experienced, whereby people so infected by these feelings, also experience them.

It's not worth the bother of killing yourself, since you always kill yourself too late.

Freedom is the alone unoriginated birthright of man, and belongs to him by force of his humanity; and is independence on the will and co-action of every other in so far as this consists with every other person's freedom.

With much care and skill power has been broken into fragments in the American township, so that the maximum possible number of people have some concern with public affairs.

They reckon ill who leave me out; When me they fly, I am the wings; I am the doubter and the doubt; And I the hymn the Brahmin sings.

Science fiction is like other writing. It is just novels and short stories with machines.

The fact is he made a prodigious blunder in commencing the attack, and now his only chance is to be silent and let people forget the exposure. I do not believe that in the whole history of science there is a case of any man of reputation getting himself into such a contemptible position.

Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.

I do not overlook the fact that there are irrationalists who love mankind, and that not all forms of irrationalism engender criminality. But I hold that he who teaches that not reason but love should rule opens up the way for those who rule by hate. (Socrates, I believe, saw something of this when he suggested that mistrust or hatred of argument is related to mistrust or hatred of man).

They are splendidly built [Italian Hospitals], the best food and drink are at hand, the attendants are very diligent, the physicians are learned, the beds and coverings are very clean, and the bedsteads are painted. As soon as a sick man is brought in, all his clothes are taken off in the presence of a notary and are faithfully kept for him. He is then laid in a handsomely painted bed with clean sheets. Two physicians are fetched at once. Attendants come with food and drink, served in immaculate glass vessels; these are not touched with as much as a finger but are brought on a tray.

Those who have ever valued liberty for its own sake believed that to be free to choose, and not to be chosen for, is an inalienable ingredient in what makes human beings human.

In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.

It is the highest service to submit the evil impulse to God through the power of love.

The slaving Poor are incapable of any Principles: Gentlemen may be converted to true Principles, by Time and Experience. The middling Rank of Men have Curiosity and Knowledge enough to form Principles, but not enough to form true ones, or correct any Prejudices that they may have imbib'd: And 'tis among the middling Rank, that Tory Principles do at present prevail most in England.

The pursuit of wealth generally diverts men of great talents and strong passions from the pursuit of power; and it frequently happens that a man does not undertake to direct the fortunes of the state until he has shown himself incompetent to conduct his own.

A man might say, with enough truth to justify a joke: "Science is what we know, and philosophy is what we don't know." But it should be added that philosophical speculation as to what we do not yet know has shown itself a valuable preliminary to exact scientific knowledge.

What is a rebel? A man who says no. 

Some say that the body is the "tomb" of the soul, their notion being that the soul is buried in the present life; and again, because by its means the soul gives any signs which it gives, it is for this reason also properly called "sign". But I think it most likely that the Orphic poets gave this name, with the idea that the soul is undergoing punishment for something; they think it has the body as an enclosure to keep it safe, like a prison, and this is, as the name itself denotes, the "safe" for the soul, until the penalty is paid, and not even a letter needs to be changed.

To abjure the notion of the "truly human" is to abjure the attempt to divinize the self as a replacement for a divinized world.

Environments work us over and remake us. It is man who is the content of and the message of the media, which are extensions of himself. Electronic man must know the effects of the world he has made above all things.

Art is not the possession of the few who are recognized writers, painters, musicians; it is the authentic expression of any and all individuality. Those who have the gift of creative expression in unusually large measure disclose the meaning of the individuality of others to those others. In participating in the work of art, they become artists in their activity. They learn to know and honor individuality in whatever form it appears. The fountains of creative activity are discovered and released. The free individuality which is the source of art is also the final source of creative development in time.

There is no good father who would want to resemble our Heavenly Father.

Whenever government assumes to deliver us from the trouble of thinking for ourselves, the only consequences it produces are those of torpor and imbecility.

Some communities will be abandoned, others will struggle along, others will split, others will flourish, gain members, and be duplicated elsewhere. Each community must win and hold the voluntary adherence of its members. No pattern is imposed on everyone, and the result will be one pattern if and only if everyone voluntarily chooses to live in accordance with that pattern of community.

I have no patience with those who say that sexual excitement is shameful and that venereal stimuli have their origin not in nature, but in sin. Nothing is so far from the truth. As if marriage, whose function cannot be fulfilled without these incitements, did not rise above blame. In other living creatures, where do these incitements come from? From nature or from sin? From nature, of course. It must borne in mind that in the apetites of the body there is very little difference between man and other living creatures. Finally, we defile by our imagination what of its own nature is fair and holy. If we were willing to evaluate things not according to the opinion of the crowd, but according to nature itself, how is it less repulsive to eat, chew, digest, evacuate, and sleep after the fashion of dumb animals, than to enjoy lawful and permitted carnal relations?

Man is as young as the risks he takes.