Charles Sanders Peirce quotes

All the evolution we know of proceeds from the vague to the definite. (Charles Sanders Peirce)
The idea does not belong to the soul; it is the soul that belongs to the idea. View quote
Charles Sanders Peirce
Effort supposes resistance. View quote
Charles Sanders Peirce
The definition of definition is at bottom just what the maxim of pragmatism expresses. View quote
Charles Sanders Peirce
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 semeiotic . View quote
Charles Sanders Peirce
A pair of statements may be taken conjunctively or disjunctively; for example, "It lightens and it thunders," is conjunctive, "It lightens or it thunders" is disjunctive. Each such individual act of connecting a pair of statements is a new monad for the mathematician . View quote
Charles Sanders Peirce
The entire universe is perfused with signs, if it is not composed exclusively of signs. View quote
Charles Sanders Peirce
Every new concept first comes to the mind in a judgment. View quote
Charles Sanders Peirce
Bad reasoning as well as good reasoning is possible; and this fact is the foundation of the practical side of logic. View quote
Charles Sanders Peirce
By an object, I mean anything that we can think, i.e. anything we can talk about. View quote
Charles Sanders Peirce
I define a Sign as anything which is so determined by something else, called its Object, and so determines an effect upon a person, which effect I call its Interpretant, that the latter is thereby mediately determined by the former. (Charles Sanders Peirce)
Every man is fully satisfied that there is such a thing as truth, or he would not ask any question. View quote
Charles Sanders Peirce
The difference between a pessimistic and an optimistic mind is of such controlling importance in regard to every intellectual function, and especially for the conduct of life, that it is out of the question to admit that both are normal, and the great majority of mankind are naturally optimistic. View quote
Charles Sanders Peirce
Consider what effects that might conceivably have practical bearings you conceive the objects of your conception to have. Then, your conception of those effects is the whole of your conception of the object. View quote
Charles Sanders Peirce
When anything is present to the mind, what is the very first and simplest character to be noted in it, in every case, no matter how little elevated the object may be? Certainly, it is its presentness . View quote
Charles Sanders Peirce
But the extraordinary insight which some persons are able to gain of others from indications so slight that it is difficult to ascertain what they are, is certainly rendered more comprehensible by the view here taken. View quote
Charles Sanders Peirce
Third, consider the insistency of an idea. The insistency of a past idea with reference to the present is a quantity which is less, the further back that past idea is, and rises to infinity as the past idea is brought up into coincidence with the present. View quote
Charles Sanders Peirce
It is terrible to see how a single unclear idea, a single formula without meaning, lurking in a young man's head, will sometimes act like an obstruction ... in an artery, hindering the nutrition of the brain, and condemning its victim to pine away in the fullness of his intellectual vigor and in the midst of intellectual plenty. View quote
Charles Sanders Peirce
Mere imagination would indeed be mere trifling; only no imagination is mere. View quote
Charles Sanders Peirce
Unless man have a natural bent in accordance with nature's, he has no chance of understanding nature at all. View quote
Charles Sanders Peirce
The recognition by one person of another's personality takes place by means to some extent identical to the means by which he is conscious of his own personality. The idea of the second personality, which is as much as to say that second personality itself, enters within the direct consciousness of the first person, and is immediately perceived as his ego, though less strongly. At the same time, the opposition between the two persons is perceived, so that the externality of the second is perceived. (Charles Sanders Peirce)
Thus far, gentlemen, I have been insisting very strenuously upon what the most vulgar common sense has every disposition to assent to and only ingenious philosophers have been able to deceive themselves about. But now I come to a category which only a more refined form of common sense is prepared willingly to allow, the category which of the three is the chief burden of Hegel's song, a category toward which the studies of the new logico-mathematicians, Georg Cantor and the like, are steadily pointing, but to which no modern writer of any stripe, unless it be some obscure student like myself, has ever done anything approaching to justice. View quote
Charles Sanders Peirce
Some words shall herein be capitalised when used, not as vernacular, but as terms defined. Thus an "idea" is the substance of an actual unitary thought or fancy; but "Idea," nearer Plato's idea of ἰδέα, denotes anything whose Being consists in its mere capacity for getting fully represented, regardless of any person's faculty or impotence to represent it. View quote
Charles Sanders Peirce
How can a past idea be present?... it can only be going, infinitesimally past, less past than any assignable past date. We are thus brought to the conclusion that the present is connected to the past by a series of real infinitesimal steps. View quote
Charles Sanders Peirce
We do not really think, we are barely conscious, until something goes wrong. View quote
Charles Sanders Peirce