Charles Sanders Peirce Quotes

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The final upshot of thinking is the exercise of volition, and of this thought no longer forms a part; but belief is only a stadium of mental action, an effect upon our nature due to thought, which will influence future thinking.

Charles Sanders Peirce
Do you call it doubting to write down on a piece of paper that you doubt? If so, doubt has nothing to do with any serious business. But do not make believe; if pedantry has not eaten all the reality out of you, recognize, as you must, that there is much that you do not doubt, in the least. Now that which you do not at all doubt, you must and do regard as infallible, absolute truth.

Charles Sanders Peirce
In those sciences of measurement which are the least subject to error — meteorology, geodesy, and metrical astronomy — no man of self-respect ever now states his results, without affixing to it its probable error; and if this practice is not followed in other sciences it is because in those the probable errors are too vast to be estimated.

Charles Sanders Peirce
The truth is, that common-sense, or thought as it first emerges above the level of the narrowly practical, is deeply imbued with that bad logical quality to which the epithet metaphysical is commonly applied; and nothing can clear it up but a severe course of logic.

Charles Sanders Peirce
Mathematics is purely hypothetical: it produces nothing but conditional propositions.

Charles Sanders Peirce
There never was a sounder logical maxim of scientific procedure than Ockham's razor: Entia non sunt multiplicanda praeter necessitatem. That is to say; before you try a complicated hypothesis, you should make quite sure that no simplification of it will explain the facts equally well.

Charles Sanders Peirce
If an opinion can eventually go to the determination of a practical belief, it, in so far, becomes itself a practical belief; and every proposition that is not pure metaphysical jargon and chatter must have some possible bearing upon practice.

Charles Sanders Peirce
There is here no need of throwing out "extreme cases." Far from that, it is precisely in the extreme cases that the power and beauty of the magic eyeglass is most apparent and most marvellous. Let me take back the word "magic," though; for the reasonableness of it is just its crowning charm.

Charles Sanders Peirce
A hypothesis is something which looks as if it might be true and were true, and which is capable of verification or refutation by comparison with facts.

Charles Sanders Peirce
One will meet, for example, the virtual assumption that what is relative to thought cannot be real. But why not, exactly? Red is relative to sight, but the fact that this or that is in that relation to vision that we call being red is not itself relative to sight; it is a real fact.

Charles Sanders Peirce
A chemical compound might be expected to be quite as much a proposition as like an algebraic invariant.

Charles Sanders Peirce
The percept is the reality. It is not in propositional form. But the most immediate judgment concerning it is abstract. It is therefore essentially unlike the reality, although it must be accepted as true to that reality. Its truth consists in the fact that it is impossible to correct it, and in the fact that it only professes to consider one aspect of the percept.

Charles Sanders Peirce
We shall do better to abandon the whole attempt to learn the truthunless we can trust to the human mind's having such a powerof guessing right that before very many hypotheses shall have been tried, intelligent guessing may be expected to lead us to one which will support all tests, leaving the vast majority of possible hypotheses unexamined.

Charles Sanders Peirce
Still, it will sometimes strike a scientific man that the philosophers have been less intent on finding out what the facts are, than on inquiring what belief is most in harmony with their system.

Charles Sanders Peirce
All the followers of science are fully persuaded that the processes of investigation, if only pushed far enough, will give one certain solution to each question to which they can be applied.... This great law is embodied in the conception of truth and reality. The opinion which is fated to be ultimately agreed to by all who investigate is what we mean by the truth, and the object represented in this opinion is the real.

Charles Sanders Peirce
The method of authority will always govern the mass of mankind; and those who wield the various forms of organized force in the state will never be convinced that dangerous reasoning ought not to be suppressed in some way.

Charles Sanders Peirce
The universe ought to be presumed too vast to have any character.

Charles Sanders Peirce
The endless variety in the world has not been created by law. It is not the nature of uniformity to originate variation, nor of law to beget circumstance.

Charles Sanders Peirce
Metaphysics has always been the ape of mathematics.

Charles Sanders Peirce
The great difference between induction and hypothesis is that the former infers the existence of phenomena such as we have observed in cases which are similar, while hypothesis supposes something of a different kind from what we have directly observed, and frequently something which it would be impossible for us to observe directly.

Charles Sanders Peirce
Three elements go to make up an idea. The first is its intrinsic quality as a feeling. The second is the energy with which it affects other ideas, an energy which is infinite in the here-and-nowness of immediate sensation, finite and relative in the recency of the past. The third element is the tendency of an idea to bring along other ideas with it.

Charles Sanders Peirce
This branch of mathematics [probability] is the only one, I believe, in which good writers frequently get results entirely erroneous.

Charles Sanders Peirce
[Science] advances by leaps; and the impulse for each leap is either some new observational resource, or some novel way of reasoning about the observations. Such novel way of reasoning might, perhaps, be considered as a new observation means, since it draws attention to reactions between facts which would previously have been passed by unperceived.

Charles Sanders Peirce
A great naturalist, as well as I can make out, is a man whose capacious skull allows of his being on the alert to a hundred different things at once, this same alertness being connected with a power of seeing the relations between different complicated sets of phenomena when they are presented in their entirety.

Charles Sanders Peirce
We should chiefly depend not upon that department of the soul which is most superficial and fallible (our reason), but upon that department that is deep and sure, which is instinct.

Charles Sanders Peirce
Truth is that concordance of an abstract statement with the ideal limit towards which endless investigation would tend to bring scientific belief, which concordance the abstract statement may possess by virtue of the confession of its inaccuracy and one-sidedness, and this confession is an essential ingredient of truth.

Charles Sanders Peirce
And what, then, is belief? It is the demi-cadence which closes a musical phrase in the symphony of our intellectual life.

Charles Sanders Peirce
Some think to avoid the influence of metaphysical errors, by paying no attention to metaphysics; but experience shows that these men beyond all others are held in an iron vice of metaphysical theory, because by theories that they have never called in question.

Charles Sanders Peirce
Fate then is that necessity by which a certain result will surely be brought to pass according to the natural course of events however we may vary the particular circumstances which precede the event.

Charles Sanders Peirce
We, one and all of us, have an instinct to pray; and this fact constitutes an invitation from God to pray.

Charles Sanders Peirce