The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don’t know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question — to doubt — to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain.<P> Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don't know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question — to doubt — to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

There is a need for what [Michael] Polanyi calls the critique of doubt. When we undertake to doubt any statement, we do so on the basis of beliefs which--in the act of doubting--we do not doubt. I can only doubt the truth of a statement on the ground of other things--usually a great many things--which I believe to be true. It is impossible at the same time to doubt both the statement, and the beliefs on the basis of which the statement is doubted.

Doubt about the fact that insight wholesomeness consists of simply observing the presently arising mental and physical phenomena is also skeptical doubt. This doubt is so subtle that it is rarely detected but is instead mistaken for investigation. This doubt masquerades as analytical knowledge. The commentary on Netti Yuttihāra explains as follows: "Doubt appears in the guise of investigation."

Once you start doubting, just like you’re supposed to doubt, you ask me if the science is true. You say no, we don’t know what’s true, we’re trying to find out and everything is possibly wrong.

The skeptic does not mean him who doubts, but him who investigates or researches, as opposed to him who asserts and thinks that he has found.

The scientific skepticism of our age professes to spring from a sense of the extreme fallaciousness of the human senses, and the liability besetting us all to deceive ourselves into a belief which gratifies the faculty of wonder. It is held as a rare and valuable gift to be able to observe a fact correctly. We are pathetically told that what a man thinks he saw, is often a mere hypothesis of his imagination as to what he saw, and may be wholly wrong.

Scepticism is not irrefutable, but obviously nonsensical, when it tries to raise doubts where no questions can be asked. For doubt can exist only where a question exists, a question only where an answer exists, and an answer only where something can be said. (6.51)

We must surrender our skepticism only in the face of rock-solid evidence. Science demands a tolerance for ambiguity. Where we are ignorant, we withhold belief. Whatever annoyance the uncertainty engenders serves a higher purpose: It drives us to accumulate better data. This attitude is the difference between science and so much else. Science offers little in the way of cheap thrills. The standards of evidence are strict. But when followed they allow us to see far, illuminating even a great darkness.

What then is man to do in this state of affairs? Is he to doubt everything, to doubt if he is awake, whether he is being pinched or burned? Is he to doubt whether he is doubting, to doubt whether he exists? No one can go that far, and I maintain that a perfectly genuine sceptic has never existed.

I take it you're not a believer, Meroka?" "Are you?" "I don't believe." He paused theatrically. "In anything. I question. I doubt. I doubt and I doubt consistently and systematically. It's called thinking scientifically." "I hope you understand what the fuck that means," Meroka said, because I sure don't." "I wouldn't expect you to, my dear. The world isn't exactly conducive to scientific thinking. Not in its present condition. But it's changing, and so must we. Those of us who can, anyway.

Why is doubt the one thing we're never skeptical of? We question other peoples' beliefs, and the more sure they are the more we doubt them. But it never occurs to us to doubt our own doubt. Question our own questions. We think our questions are answers.

Because a doubt is not a denial. Doubt is a powerful tool, and it should be applied to history.

If you’re only sceptical, then no new ideas make it through to you. You never learn anything. You become a crochety misanthrope convinced that nonsense is ruling the world. (There is, of course, much data to support you.) Since major discoveries in the borderlines of science are rare, experience will tend to confirm your grumpiness. But every now and then a new idea turns out to be on the mark, valid and wonderful. If you’re too resolutely and uncompromisingly sceptical, you’re going to miss (or resent) the transforming discoveries in science, and either way you will be obstructing understanding and progress. Mere scepticism is not enough.