Nature is not a temple but a workshop, and man is the workman in it. Men judge things according to their own feelings; they forget that in time all things change their aspect.

It is not the neutrality of the judge that makes justice, but his passionate will to do right. And the same is true of the scientist: it is not his indifference to truth but his passionate love of it that makes him a scientist.

It is not the neutrality of the judge that makes justice, but his passionate will to discover what is true. A judge who merely balances probabilities has abdicated his function.

We are what we repeatedly do. Excellence, then, is not an act, but a habit. Yet the most dangerous habit is the habit of certainty — for it closes the very faculties by which excellence is sustained.

The aim of science is not to open a door to infinite wisdom, but to set a limit to infinite error.

It is not the consciousness of men that determines their existence, but their social existence that determines their consciousness. And yet every age believes the opposite — that it thinks its way into its conditions, rather than being thought by them.

It is not the possession of truth, but the success which attends the seeking after it, that enriches the seeker and brings happiness to him.

Most people think that if they just had more information, they'd make better decisions. But the problem is rarely informational — it's structural. The question isn't 'what do I know?' but 'what am I incentivized to see?'

It is not the answer that enlightens, but the question. A question is a net cast into the unknown; the answer is only what the net happens to catch.

The tendency of the casual mind is to pick out or stumble upon a sample which supports or defies its prejudices, and then to make it the representative of a whole class.

The owl of Minerva spreads its wings only with the falling of the dusk. Philosophy comes too late to teach the world what it should have been; it only shows what the world has been.

The universe is not required to be in perfect harmony with human ambition. And yet the history of science is a history of that ambition refusing to accept the universe's indifference.

The thing about Cassandra is not that no one believed her, but that everyone had a reason not to. Truth, when it is inconvenient, does not lack for enemies — it lacks for witnesses.

The thing that astonishes me is that the geologists and biologists seem quite unaware of the philosophical chaos that underlies their own work — they proceed as though the universe were already explained, and their only task were to fill in the details.

We are apt to think that our ideas are the measure of things, and that silence means ignorance. But nature has other standards than ours, and there is a vast deal going on in the world which we cannot translate into human speech.

It is not so much that I have a new theory of the universe to offer, as that I wish to call attention to certain habits of mind which prevent men from seeing what is before their eyes.

It is not enough to have a good mind; the main thing is to use it well. And yet there are persons who flatter themselves that they think very clearly, who in reality only think with the prejudices of their age.

Every man takes the limits of his own field of vision for the limits of the world. This is an error of the intellect as inveterate as it is pernicious, and yet it is one that we commit every day without knowing it.

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your children for a picnic on a doubtful day, they will not enjoy themselves unless they are certain it will be fine.

The most erroneous stories are those we think we know best — and therefore never scrutinize or question.

It is not the answer that enlightens, but the question. And to ask the right question, one must first unlearn the comfortable certainty that one already knows.

The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed, in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible.

It is not the answer that enlightens, but the question. And to ask the right question is already to know the direction of the answer.

The most valuable of all talents is that of never using two words when one will do. And the most dangerous of all follies is to mistake the map for the territory.

We are compelled to feel that the world of our experience is not the world of reality, and yet it is only through the world of experience that we can come to know any world at all.

To be sheltered from the winds of doctrine is to be kept from contact with reality. The man who is protected against every draught of opinion is kept from the real world; but then, what is the real world?

The tendency of modern science is to reduce all natural phenomena to the action of matter, and to explain the complex by the simple. But this tendency has its dangers; it may lead us to forget that the simple is always an abstraction, and that the real world is infinitely complex.

The whole of science is nothing more than a refinement of everyday thinking. And yet this refinement is purchased at a terrible price — the price of losing touch with the concrete and the living, and of substituting for it a pale, bloodless abstraction.

It is a great mistake to think that the motive which leads a man to seek knowledge is always a desire for it. Much more often it is a desire for certainty, and the two are very different things.

We are as much as we see. Faith is sight and knowledge. The hands only serve the eyes.

Every invalid is a physician. What does it matter that his prescriptions are all for himself?

The thing about Cassandra is not that she was disbelieved, but that she was believed and then forgotten — which is the commoner fate of prophets.

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your hypothesis seriously enough, it will generate predictions; and if the predictions are wrong, you must abandon the hypothesis. To seek for certainty where the subject-matter does not permit it is to mistake the nature of the inquiry.

The most thought-provoking thing in our thought-provoking time is that we are still not thinking. This is a sobering fact when we consider how much has been done, and how little we have understood of what has been done.

The universe is not indifferent to intelligence; it simply has not yet been asked the right questions. But the asking itself changes both the asker and the universe.

The universe is not required to be in perfect harmony with human ambition. And yet the history of science is largely the history of our stubborn insistence that it must be.

A fact is like a sack — it won't stand up till you've put something into it. To make a fact stand up, you have to put into it all the reason and feeling that caused it in the first place.

We are beginning to see that to ask what is the use of science is as vulgar as to ask what is the use of a sunset, and almost as stupid.

The tendency of modern scientific teaching is to neglect the great books, to lay far too much stress on the minute study of details, and to overlook the great generalizations. It is the study of generalizations that liberates the human mind.

The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion.

The moment we want to believe something, we suddenly see all the arguments for it, and become blind to the arguments against it.

The universe is a series of collapsed probabilities. What we call history is merely the thread that happened to hold — and we mistake the thread for the loom.

The universe is not required to be in perfect harmony with human ambition. It is indifferent to our need for certainty, and it is precisely this indifference that makes the pursuit of understanding so urgent.