Our weapons are the ironic mind against the literal: the open mind against the credulous; the courageous pursuit of truth against the fearful and abject forces who would set limits to investigation (and who stupidly claim that we already have all the truth we need). Perhaps above all, we affirm life over the cults of death and human sacrifice and are afraid, not of inevitable death, but rather of a human life that is cramped and distorted by the pathetic need to offer mindless adulation, or the dismal belief that the laws of nature respond to wailings and incantations.
Ours is a particularly unhistorical age. It is the spirit of the times to be interested in the latest products, not only of our advancing technologies, but also of our writers and thinkers and perhaps especially of our moviemakers and musical performers. Paying attention only to the present, however, is like hearing just snatches of a conversation. Its meaning is unclear, and one is likely to give it an interpretation that it will not bear. For we are engaged in a conversation, one that reaches back to earliest times and that, barring catastrophe, will be carried on beyond us.
There may be a limit to what the human mind can figure out about our universe. But how presumptuous it would be for me to claim that if I can't solve a problem, neither can any other person who has ever lived or who will ever be born. Suppose Galileo and Laplace had felt that way? Better yet, what if Newton had not? He might then have solved Laplace's problem a century earlier, making it possible for Laplace to cross the next frontier of ignorance... Science is a philosophy of discovery. Intelligent design is a philosophy of ignorance. You cannot build a program of discovery on the assumption that nobody is smart enough to figure out the answer to a problem. Once upon a time, people identified the god Neptune as the source of storms at sea. Today we call these storms hurricanes. We know when and where they start. We know what drives them. We know what mitigates their destructive power. And anyone who has studied global warming can tell you what makes them worse. The only people who still call hurricanes “acts of God” are the people who write insurance forms.
There are many hypotheses in science that are wrong. That's perfectly alright; it's the aperture to finding out what's right. Science is a self-correcting process. To be accepted, new ideas must survive the most rigorous standards of evidence and scrutiny. The worst aspect of the Velikovsky affair is not that many of his ideas were wrong or silly or in gross contradiction to the facts; rather, the worst aspect is that some scientists attempted to suppress Velikovsky's ideas. The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge and there is no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system, and the history of our study of the solar system shows clearly that accepted and conventional ideas are often wrong and that fundamental insights can arise from the most unexpected sources.
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.
