The Burden Of Skepticism
Carl Sagan
What is skepticism? It’s nothing very esoteric. We encounter it every day. When we buy a used car, if we are the least bit wise we will exert some residual skeptical powers—whatever our education has left to us. You could say, “Here’s an honest-looking fellow. I’ll just take whatever he offers me.” Or you might say, “Well, I’ve heard that occasionally there are small deceptions involved in the sale of a used car, perhaps inadvertent on the part of the salesperson,” and then you do something. You kick the tires, you open the doors, you look under the hood. (You might go through the motions even if you don’t know what is supposed to be under the hood, or you might bring a mechanically inclined friend.) You know that some skepticism is required, and you understand why. It’s upsetting that you might have to disagree with the used-car salesman or ask him questions that he is reluctant to answer. There is at least a small degree of interpersonal confrontation involved in the purchase of a used car and nobody claims it is especially pleasant. But there is a good reason for it—because if you don’t exercise some minimal skepticism, if you have an absolutely untrammeled credulity, there is probably some price you will have to pay later. Then you’ll wish you had made a small investment of skepticism.
Now this is not something that you have to go through four years of graduate school to understand. Everybody understands this. The trouble is, a used car is one thing but television[,] commercials or pronouncements by presidents and party leaders are another. We are skeptical in some areas but unfortunately not in others.
For example, there is a class of aspirin commercials that reveals the competing product to have only so much of the painkilling ingredient that doctors recommend most—they don’t tell you what the mysterious ingredient is—whereas their product has a dramatically larger amount (1.2 to 2 times more per tablet). Therefore you should buy their product.
But why not just take two of the competing tablets? You’re not supposed to ask. Don’t apply skepticism to this issue. Don’t think. Buy.
. . .
If you were to drop down on Earth at any time during the tenure of humans you would find a set of popular, more or less similar, belief systems. They change, often very quickly, often on time scales of a few years: But sometimes belief systems of this sort last for many thousands of years. At least a few are always available. I think it’s fair to ask why. We are Homo sapiens. That’s the distinguishing characteristic about us, that sapiens part. We’re supposed to be smart. So why is this stuff always with us? Well, for one thing, a great many of these belief systems address real human needs that are not being met by our society. There are unsatisfied medical needs, spiritual needs, and needs for communion with the rest of the human community. There may be more such failings in our society than in many others in human history. And so it is reasonable for people to poke around and try on for size various belief systems, to see if they help.
For example, take a fashionable fad, channeling. It has for its fundamental premise, as does spiritualism, that when we die we don’t exactly disappear, that some part of us continues. That part, we are told, can reenter the bodies of human and other beings in the future, and so death loses much of its sting for us personally. What is more, we have an opportunity, if the channeling contentions are true, to make contact with loved ones who have died.
Speaking personally, I would be delighted if reincarnation were real. I lost my parents, both of them, in the past few years, and I would love to have a little conversation with them, to tell them what the kids are doing, make sure everything is all right wherever it is they are. That touches something very deep. But at the same time, precisely for that reason, I know that there are people who will try to take advantage of the vulnerabilities of the bereaved. The spiritualists and the channelers better have a compelling case.
Or take UFOs, the contention that beings in spaceships from other worlds are visiting us all the time. I find that a thrilling idea. It’s at least a break from the ordinary. I’ve spent a fair amount of time in my scientific life working on the issue of the search for extraterrestrial intelligence. Think how much effort I could save if those guys are coming here. But when we recognize some emotional vulnerability regarding a claim, that is exactly where we have to make the firmest efforts at skeptical scrutiny. That is where we can be had.
. . .
Occasionally, by the way, I get a letter from someone who is in “contact” with an extraterrestrial who invites me to “ask anything.” And so I have a list of questions. The extraterrestrials are very advanced, remember. So I ask things like, “Please give a short proof of Fermat’s Last Theorem.” Or the Goldbach Conjecture. And then I have to explain what these are, because extraterrestrials will not call it Fermat’s Last Theorem, so I write out the little equation with the exponents. I never get an answer. On the other hand, if I ask something like “Should we humans be good?” I always get an answer. I think something can be deduced from this differential ability to answer questions. Anything vague they are extremely happy to respond to, but anything specific, where there is a chance to find out if they actually know anything, there is only silence.
The French scientist Henri Poincaré remarked on why credulity is rampant: “We also know how cruel the truth often is, and we wonder whether delusion is not more consoling.” That’s what I have tried to say with my examples. But I don’t think that’s the only reason credulity is rampant. Skepticism challenges established institutions. If we teach everybody, let’s say high school students [let’s say grade school], the habit of being skeptical, perhaps they will not restrict their skepticism to aspirin commercials and 35,000-year-old channelers (or channelees). Maybe they’ll start asking awkward questions about economic, or social, or political, or religious institutions. Then where will we be? Skepticism is dangerous. That’s exactly its function, in my view. It is the business of skepticism to be dangerous. And that’s why there is a great reluctance to teach it in the schools. That’s why you don’t find a general fluency in skepticism in the media. On the other hand, how will we negotiate a very perilous future if we don’t have the elementary intellectual tools to ask searching questions of those nominally in charge, especially in a democracy?
. . .
It seems to me what is called for is an exquisite balance between two conflicting needs: the most skeptical scrutiny of all hypotheses that are served up to us and at the same time a great openness to new ideas. Obviously those two modes of thought are in some tension. But if you are able to exercise only one of these modes, which ever one it is, you’re in deep trouble. If you are only skeptical, then no new ideas make it through to you. You never learn anything new. You become a crotchety old person convinced that nonsense is ruling the world. (There is, of course, much data to support you.) But every now and then, maybe once in a hundred cases, a new idea turns out to be on the mark, valid and wonderful. If you are too much in the habit of being skeptical about everything, you are going to miss or resent it, and either way you will be standing in the way of understanding and progress. On the other hand, if you are open to the point of gullibility and have not an ounce of skeptical sense in you, then you cannot distinguish the useful ideas from the worthless ones. If all ideas have equal validity then you are lost, because then, it seems to me, no ideas have any validity at all.
Some ideas are better than others. The machinery for distinguishing them is an essential tool in dealing with the world and especially in dealing with the future. And it is precisely the mix of these two modes of thought that is central to the success of science.
Really good scientists do both. On their own, talking to themselves, they churn up huge numbers of new ideas, and criticize them ruthlessly. Most of the ideas never make it to the outside world. Only the ideas that pass through a rigorous self-filtration make it out and are criticized by the rest of the scientific community. It sometimes happens that ideas that are accepted by everybody turn out to be wrong, or at least partially wrong, or at least superseded by ideas of greater generality. And, while there are of course some personal losses—emotional bonds to the idea that you yourself played a role in inventing—nevertheless the collective ethic is that every time such an idea is overthrown and replaced by something better the enterprise of science has benefited. In science it often happens that scientists say, “You know that’s a really good argument; my position is mistaken,” and then they actually change their minds and you never hear that old view from them again. They really do it. It doesn’t happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that has happened in politics or religion. It’s very rare that a senator, say, replies, “That’s a good argument. I will now change my political affiliation.”
After my article “The Fine Art of Baloney Detection” came out in Parade (Feb. 1, 1987), I got, as you might imagine, a lot of letters. Sixty-five million people read Parade. In the article I gave a long list of things that I said were “demonstrated or presumptive baloney”—thirty or forty items. Advocates of all those positions were uniformly offended, so I got lots of letters. I also gave a set of very elementary prescriptions about how to think about baloney—arguments from authority don’t work, every step in the chain of evidence has to be valid, and so on. Lots of people wrote back, saying, “You’re absolutely right on the generalities; unfortunately that doesn’t apply to my particular doctrine.” For example, one letter writer said the idea that intelligent life exists outside the Earth is an excellent example of baloney. He concluded, “I am as sure of this as of anything in my experience. There is no conscious life anywhere else in the universe. Mankind thus returns to its rightful position as center of the universe.”
Another writer again agreed with all my generalities, but said that as an inveterate skeptic I have closed my mind to the truth. Most notably I have ignored the evidence for an Earth that is six thousand years old. Well, I haven’t ignored it; I considered the purported evidence and then rejected it. There is a difference, and this is a difference, we might say, between prejudice and postjudice. Prejudice is making a judgment before you have looked at the facts. Postjudice is making a judgment afterwards. Prejudice is terrible, in the sense that you commit injustices and you make serious mistakes. Postjudice is not terrible. You can’t be perfect of course; you may make mistakes also. But it is permissible to make a judgment after you have examined the evidence. In some circles it is even encouraged.
I believe that part of what propels science is the thirst for wonder. It’s a very powerful emotion. All children feel it. In a first grade classroom everybody feels it; in a twelfth grade classroom almost nobody feels it, or at least acknowledges it. Something happens between first and twelfth grade, and it’s not just puberty. Not only do the schools and the media not teach much skepticism, there is also little encouragement of this stirring sense of wonder. Science and pseudoscience both arouse that feeling. Poor popularizations of science establish an ecological niche for pseudoscience.
If science were explained to the average person in a way that is accessible and exciting [without sensationalizing it], there would be no room for pseudoscience. But there is a kind of Gresham’s Law by which in popular culture the bad science drives out the good. And for this I think we have to blame, first, the scientific community ourselves for not doing a better job of popularizing science, and second, the media, which are in this respect almost uniformly dreadful. Every newspaper in America has a daily astrology column. How many have even a weekly astronomy column? And I believe it is also the fault of the educational system. We do not teach how to think. This is a very serious failure that may even, in a world rigged with 60,000 nuclear weapons, compromise the human future.
I maintain there is much more wonder in science than in pseudoscience. And in addition, to whatever measure this term has any meaning, science has the additional virtue, and it is not an inconsiderable one, of being true.
Copyright ©1987 by Carl Sagan
![[art]by[odo]](https://artbyodo.net/wordpress/wp-content/uploads/2011/03/cropped-Header.jpg)
