About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Saturday, September 17, 2005

The lonely life of skeptics and the end of science

I like the word "skeptic," as in someone who habitually doubts accepted beliefs. My favorite skeptic of all time is David Hume, who talked about "positive skepticism," meaning that a skeptic is not a curmudgeon who simply rejects other people's opinions out of spite, but rather a careful thinker who accepts notions in proportion to the available evidence. Consequently, a good skeptic is not dogmatic, but on the contrary ready to change his position whenever warranted.

Nevertheless, I am constantly reminded of how naturally despised skeptics are, simply because they have a tendency to question people's (mostly irrational) cherished beliefs, an annoying (to most) habit of probing beyond the superficial reasons people often give in support of their half-baked ideas.

I was reminded of this during my recent trip to Cambridge for a scientific meeting. During a post-lunch break over (awful) coffee, I was engaged in a pleasant conversation with three really smart colleagues, all of them biologists, with an excellent training in statistical analysis and a host of published papers were they obviously demonstrated their abilities as researchers, logical thinkers, and -- especially -- their careful attention to the importance of argument backed by sound empirical evidence.

Right, until, of course, the conversation somehow wandered over philosophical territory. I don't recall exactly how it happened, but we began to talk about the possibility of the so-called "end of science." Much has been written about this, and most of it is rubbish. But the basic idea, I thought, is undeniably sound: science is about asking big questions concerning how the world works; there are a limited number of such questions; moreover, human beings are epistemically limited (meaning that there are limits to what we can know, given our finiteness, availability of resources, etc.); ergo, one of these days science will end in the sense that we will either have an answer to all the big questions (e.g., consciousness, origin of life, evolution, fundamental structure of matter, etc.), or we will run into some questions for which our epistemic limits will never be overcome (possible examples include what was there before the big bang, the possibility of parallel universes, etc.). Everything else will be stamp collecting, or seeking solutions to local puzzles that may be practically important, or even mildly interesting, but will not constitute big questions.

Wow, did that sort of reasoning ruffle some of my colleagues' feathers! The first argument against the end of science was that the universe may be infinite, and so would the number of questions we could ask. This is such a philosophically naive chain of reasoning that it is hard to believe it was proposed to me in all seriousness by an eminent biologist. First, of course, the universe may very well not be infinite (this is an empirical question). Second, there are some mathematical models that depict the universe as without boundaries (and therefore "infinite" in some sense) and yet limited, for example shaped like a donut. Third, and most importantly, the finiteness of the universe has nothing logically to do with the finiteness of the number of big questions in science. To see this, just consider a simple algorithm to produce an infinite series of numbers (like "X = X+1; reiterate"). Clearly, the output is infinite; but equally clearly there ain't much of interest that can be asked about the algorithm (yes, I'm aware of the psychological caveat that "interest" is a rather subjective matter, and yet you'd be amazed how relatively easy it is to have scientists agree on what are the really interesting questions about nature).

A second argument put forth by my colleague was that, "you never know, new questions may come up." The "you never know" argument against skepticism is perhaps the most popular one, and it is often considered to be either a clincher, or at least to clearly show that the skeptic is in fact close-minded for not even considering the possibility that he is wrong (indeed, my colleague followed through by asking me whether I was absolutely sure of my position -- which of course borders on a logical fallacy, because at that point he was beginning to shift from discussing the question at hand to attacking the personality of his intellectual opponent). But of course there are plenty of things we know to be impossible (think of many mathematical theorems as setting definite limits to logical possibilities). More broadly, the point is often to evaluate the relative merits of two positions, which means that both sides have to come up with a reasonable argument. To dismiss the other's view just on the ground that something is "possible" (without further elaboration of how this might be the case) is a cheap intellectual shot (and one that has been elaborated upon to perfection by religious apologists).

In the end, it was clear that my colleague -- like so many non-scientists who really dislike skeptics -- was simply uncomfortable with the very idea of a limit. He preferred to think of science as an unbounded set of possibilities, with few or no constraints. Very much like someone who believes in the supernatural, or is sympathetic to pseudoscience. It's the infatuation with mystery for mystery's sake, the very thing that skeptics threaten at every turn, and the main reason we are so despised. But of course skepticism is no threat either to human creativity, or to what we can actually do in practice. My discussion with my biology colleague was purely academic, in the strict sense of the word: neither of us seriously expects science to "end" any time soon, certainly not during our life times. And one can hardly make the argument that just because there are limits one's imagination becomes too constrained (on the contrary, imagination yields the best results when it does work within some rules: compare a movie whose story is internally consistent with one made of random sequences, completely unconnected to each other).

Reason and skepticism are not enemies of imagination and possibility. On the contrary, they are our most invaluable allies to make sense of the world.


  1. This reminded me of a small incident when I was about 10 or 11 years old. There was some discussion going on between me and one or two friends of mine at school. I can't for the life of me recall what it was about or any other circunstance at the time, but sure it was no phylosophical discussion.

    At a certain point, one of my friends called me a "skeptic", and it was clear by his demeanor that his intent was to insult. I had no idea what that meant, and probably he didn't either (he might have known, and it might have been a legitimate call, but as I can't remember the discussion per se, we'll never know...). I didn't mind the "insult", as is my nature most of the time, but I obviously did not forget it.

    So it is funny how, so many years later, I came to the appropriate answer: Thanks!


  2. Massimo, here in South Africa I read every word you write.
    But I am annoyed by your style of typing. Please acquire the habit of typing a space after every ".", every ",", every ":", and every ";" in your writing. It will make for easier reading. But I remain a fan.
    Jan Lessing

  3. Massimo, I see that even my comment was edited in cyberspace to omit the spaces I am appealing for. (Space) typed after the "."
    Now I don't blame you.
    Please continue typing.
    Jan Lessing.

  4. Jan, thanks for the kind words. As you've found out, I have less control over the formatting here than I would like, and I really can't bring myself to use double spaces after commas and periods... :-)

  5. Massimo, I don't seem to understand what the "end of science" argument has to do with being a sceptic or not. As an outsider & based on your account of the discussion, I could easily label your colleague an open minded skeptic & you a dogmatic.

  6. Aorstan, interesting, since your reaction is exactly what prompted my post. The point I was trying to make is that "it's possible" (one of my colleague's main arguments against the end of science) is not an argument at all. To vaguely state that something is possible only makes it appear as if the person advancing it is open-minded, thereby putting an unfair burden on the skeptic (after all, I never claimed to know for sure that science will run out of big questions, I only made a logical argument that it should, sooner or later...).

    Let's put it this way: it's possible that there are unicorns out there, but I don't think I'm close minded because I don't believe it. The arguments in favor of the existence of unicorns are much less compelling than those against it.

  7. Yes, but the claim that the end of science may not be near is not as outrageous as the claim that there are unicorns. There has never been any good evidence that are/were unicorns, but there have been times in the history of science when people thought most everything that needed to be known was known.

    For example, one could have easily claimed near the end of the 19th century that the end of physics was near except for a few unexplained experiments. But, then look what happened.

    Perhaps a better example would be the case of the ivory-billed woodpeckers. Do they still exist or not? If I say that it is possible that they exist, am I a dogmatic or a skeptic? I think I am neither or a little bit of both. I am simply withholding judgement until there is more evidence.

  8. There are indeed good examples in the history of science when people thought they had most things figured out, only for new horizons to be opened up by new discoveries. No question about it.

    But my point is that this sort of things (which, by the way, is an inference based on induction, a notoriously limited logical device) should have a limit. The sun has "risen" for billions of years, and will do so for billions more. But that doesn't mean it will last forever. Indeed, we have very good reasons to believe it will not.

    Nevertheless, the really interesting point here is what counts as "dogmatism." I might write more about it on this blog soon.

  9. Ironically, skeptics almost automatically deny the possibility of "certainty" but are usually quite certain enough of their own skepticism to stick with it.


    And the lack of being able to put stock (and or faith) in some issue as being quite certainly and without reservation true, that may very well put an effective end to good science.



  10. Hi Massimo,

    Your argument that our finiteness suggests a limit to science is fallacious. They were correct to be skeptical. We can draw upon increasing resources to emulate an arbitrarily large mind or machine. As a Turing machine is not limited by being controlled by a finite state machine, as long as it can draw upon an unlimited tape. Your argument then falls upon the claim that the Universe can represent no number larger than a certain size. In a mathematical sense, it would not be The Universe. A wild speculation considering the rate at which it has grown over the 20th century :). No matter how much a philosopher knows, virtually every question remains far beyond his capabilities. It is similarly strange that you would suggest that a "skeptic" would reach a state of mind from which he would expect to never change his mind on anything of significance. Claims of the "end of science" are at best pitifully parochial.

  11. Finitist,

    I think you are confusing several issues. Mathematical infinity has (as far as I can tell) nothing to do with how many meanigful/interesting questions one can ask in science.

    Second, realizing that a particular human endeavor (like science) may some day reach a limit has nothing to do (again, as far as I can see) with the open-mindedness of a skeptic.

    It seems to me that the claim of an infinite number of possible questions is hard to accept on its face, and that it therefore requires some arguments to butress it. The only argument I've heard so far is "you never know what comes next." Weak.


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