Quotes from Charles Sanders Peirce

Every new concept first comes to the mind in a judgment.

When I communicate my thought and my sentiments to a friend with whom I am in full sympathy, so that my feelings pass into him and I am conscious of what he feels, do I not live in his brain as well as in my own—most literally?

Truly, that reason upon which we plume ourselves, though it may answer for little things, yet for great decisions is hardly surer than a toss-up.

The idea does not belong to the soul; it is the soul that belongs to the idea.

Doubt is an uneasy and dissatisfied state from which we struggle to free ourselves and pass into the state of belief while the latter is a calm and satisfactory state which we do not wish to avoid, or to change to a belief in anything else.

Do not block the way of inquiry.

All the evolution we know of proceeds from the vague to the definite.

Unless man have a natural bent in accordance with nature's, he has no chance of understanding nature at all.

Every man is fully satisfied that there is such a thing as truth, or he would not ask any question.

If man were immortal he could be perfectly sure of seeing the day when everything in which he had trusted should betray his trust, and, in short, of coming eventually to hopeless misery. He would break down, at last, as every good fortune, as every dynasty, as every civilization does. In place of this we have death.

All human affairs rest upon probabilities, and the same thing is true everywhere. If man were immortal he could be perfectly sure of seeing the day when everything in which he had trusted would betray his trust, and, in short, of coming eventually to hopeless misery. He would break down, at last, as every great fortune, as every dynasty, as every civilization does. In place of this we have death.

We think only in signs.

Let us not pretend to doubt in philosophy what we do not doubt in our hearts.

Let it be considered that what is more wholesome than any particular belief is integrity of belief; and that to avoid looking into the support of any belief from a fear that it may turn out rotten is quite as immoral as it is disadvantageous.

I hear you say: 'All that is not /fact/ : it is poetry'. Nonsense! Bad poetry is false, I grant; but nothing is truer than true poetry. And let me tell the scientific men that the artists are much finer and more accurate observers than they are, except of the special minutiae that the scientific man is looking for.

Few persons care to study logic, because everybody conceives himself to be proficient enough in the art of reasoning already. But I observe that this satisfaction is limited to one's own ratiocination, and does not extend to that of other men.

If liberty of speech is to be untrammeled from the grosser forms of constraint, the uniformity of opinion will be secured by a moral terrorism to which the respectability of society will give its thorough approval.

The elements of every concept enter into logical thought at the gate of perception and make their exit at the gate of purposive action; and whatever cannot show its passports at both those two gates is to be arrested as unauthorized by reason.

Notwithstanding all that has been discovered since Newton 's time, his saying that we are little children picking up pretty pebbles on the beach while the whole ocean lies before us unexplored remains substantially as true as ever, and will do so though we shovel up the pebbles by steam shovels and carry them off in carloads.

Abduction is the process of forming an explanatory hypothesis. It is the only logical operation which introduces any new idea; for induction does nothing but determine a value and deduction merely evolves the necessary consequences of a pure hypothesis.

What the pragmatist has his pragmatism for is to be able to say, Here is a definition and it does not differ at all from your confusedly apprehended conception because there is no practical difference.

Signs are of three classes, namely, Icons (or images), Indices, and Symbols. Article 6. An icon is a sign which stands for its object because as a thing perceived it excites an idea naturally allied to the idea that object would excite.

Are you sure twice two are four? Not at all. A certain percentage of the human race are insane and subject to illusions. It may be you are one of them, and that your idea that twice two is four is a lunatic notion, and your seeming recollection that other people think so, the baseless fabric of a vision.

it has never been in my power to study anything,—mathematics, ethics, metaphysics, gravitation, thermodynamics, optics, chemistry, comparative anatomy, astronomy, psychology, phonetics, economics, the history of science, whist, men and women, wine, metrology, except as a study of semiotic.