Charles Sanders Peirce Quotes

In philosophy you're never 100% sure. You're always undermining what you think you know. That's always been my philosophy and my intellectual ethos.

Inquiry is fatal to certainty.

We cannot infer that because sciences of things divine and human are full of controversies and quarrels, therefore their whole subject-matter is uncertain ; for there have been many persons so enamoured of contradiction, as to turn into ridicule geometrical axioms.

Descartes, the father of modern philosophy ... would never-so he assures us-have been led to construct his philosophy if he had had only one teacher, for then he would have believed what he had been told; but, finding that his professors disagreed with each other, he was forced to conclude that no existing doctrine was certain.

Belief in truth begins with doubting all that has hitherto been believed to be true.

Truth is something that we can attempt to doubt, and then perhaps, after much exertion, discover that part of the doubt is not justified.

I have teken refuge in the doctrine that advises one not to seek tranquility in certainty but in permanently suspended judgement.

He believed in the primacy of doubt, not as a blemish upon our ability to know, but as the essence of knowing.

If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.

This notion [skepticism] is more clearly understood by asking "What do I know?"

Philosophy begins in wonder.

If a man will begin with certainties, he shall end in doubts, but if he will content to begin with doubts, he shall end in certainties.

Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.

If you would be a real seeker after truth, you must at least once in your life doubt, as far as possible, all things.

Science is what you know. Philosophy is what you don't know.

Not to be absolutely certain is, I think, one of the essential things in rationality.

We'd all like to be certain of what we know, but I think the most important question is to ask yourself do you really know what you know?

But is all this true?" said Brutha. Didactylos shrugged. "Could be. Could be. We are here and it is now. The way I see it is, after that, everything tends towards guesswork." "You mean you don't KNOW it's true?" said Brutha. "I THINK it might be," said Didactylos. "I could be wrong. Not being certain is what being a philosopher is all about.

By doubting we come to questioning, and by questioning we perceive the truth.

We absolutely must leave room for doubt or there is no progress and no learning. There is no learning without having to pose a question. And a question requires doubt. People search for certainty. But there is no certainty.

I am a philosopher, not a scientist, and we philosophers are better at questions than answers.

All that belongs to human understanding, in this deep ignorance and obscurity, is to be sceptical, or at least cautious, and not to admit of any hypothesis whatever, much less of any which is supported by no appearance of probability.

I've gone through most of my life not believing anything. Either I know or I don't know, or I think.

But without doubts, without a standpoint reached through questionings, human beings can't acquire knowledge.

Is there any knowledge in the world which is so certain that no reasonable man could doubt it?