Here goes an old joke about skepticism. Two skeptics meet at a convention. One of them says, “Hi, I don’t believe we’ve met.” The other responds: “I don’t believe you don’t believe we met…”
Skeptics have that sort of reputation, or worse. A friend of mine, who has been working for many years on behalf of a group known as New York City Skeptics, tells me that he avoids using “the s-word” in public, because a typical reaction is something along the lines of “ah, those are the people that don’t believe in anything, right?”
In fact, skepticism comes from the Latin scepticus, which itself derives from the Greek skeptikos, meaning “inquiring, reflective.” To be a skeptic, then, means to reflect and inquire about things. A most commendable attitude, I should think!
And yet, it isn’t just the person in the street who is distrustful of skeptics. Many professional philosophers are too! Here is Kant venting his frustration about a particularly vexing (to him) example of skepticism:
“It … remains a scandal of philosophy and universal human reason that the existence of things outside us … should have to be assumed merely on faith, and that if it occurs to anyone to doubt it, we should be unable to answer him with a satisfactory proof.” (Refutation of Idealism, in Critique of Pure Reason)
Though Kant, technically speaking, was talking about idealism (the notion that reality is the result of the activity of some kind of mind, usually God’s), skepticism is a close cousin, and Kant himself famously said that he was awakened from his “dogmatic slumber” by reading the skeptic David Hume and his critique of the concept of causality, which spurred Kant into action and try to do away with both skepticism and idealism.
Given my enduring interest in skepticism in all its forms, I’ve been reading Skepticism: From Antiquity to the Present, edited by D.E. Machuca and B. Reed. I will return to this book in several future posts, as I am planning a “Profiles in Skepticism” limited series. But for the purposes of the present essay I was struck by what one of the editors, Baron Reed, writes in his introduction to the section on contemporary skepticism:
“Many of the most significant developments in recent epistemology have been motivated, at least in part, as responses to global and perceptual skeptical challenges.”
Really? I would have thought the issue to be settled long ago: the skeptical challenge is insurmountable, so the only reasonable thing to do is to accept it and move on. Or even better: to embrace it before we move on!
What exactly is this skeptical challenge? We’ve talked about it before: in its basic version it is known as Agrippa’s trilemma, after the first century Pyrrhonian skeptic by the same name. In essence, Agrippa maintained that whenever someone makes a claim to knowledge, of any kind, we are perfectly within our right to ask how they know that what they are saying is true. According to Agrippa, our interlocutor has three and only three options available:
(i) To engage in an infinite regress, where claim A is justified by claim B, which is justified by claim C, and so on ad infinitum.
(ii) To present some sort of circular reasoning, where A is justified by B, which is justified by C, which—eventually—is in turn justified by A.
Or: (iii) To introduce an arbitrary (“dogmatic”) stopping point, basically asserting that some kind of belief is “properly fundamental” and does not need justification.
The problem facing the non-skeptic is two-fold: on the one hand, none of the three strategies above is considered epistemologically kosher. On the other hand, those are the only three strategies available.
To reiterate: engaging in an infinite regress, circular reasoning, or dogmatic assumptions is really, really bad form in philosophy. Which is why Reed goes through a long series of alleged responses to the skeptical challenge. Here is a taste:
Foundationalism: Somehow, we can identify a class of properly fundamental beliefs from which to reconstruct our edifice of knowledge. But there is of course great disagreement about what kinds of beliefs might, in fact, be “properly fundamental.” Descartes certainly tried (remember? “I am therefore I think”), and failed abysmally. Many philosophers in fact despair of ever finding such a foundational class of beliefs, and even some who think it may be possible are not at all confident that those beliefs would provide enough building blocks to justify much else.
Coherentism: Perhaps circularity isn’t so bad. After all, math and logic are, ultimately, circular! Yes, but math and logic have to do with statements that are true by definition. Here we are concerned with justifying beliefs about the actual, physical world, and circularity in this case is really bad because nothing in the outside world is logically, necessarily entailed by something else.
Infinitism: Infinite regresses may be acceptable, under certain conditions. But why?, and what distinguishes—in principle—an acceptable from an unacceptable infinite regress? In practice, how would one go, exactly, justifying a belief by lining up an infinite number of reasons?
The three options above, you may have noticed, correspond to biting into one of the three bullets fired by Agrippa. While my understanding is that foundationalism is the option most frequently favored by epistemologists, none of the three are really palatable, and certainly not widely accepted.
There are other possibilities, though:
Disjunctivism: If I’m having a waking experience I’m in a different (disjunct) state compared to when I’m dreaming of the same experience, and that suggests that veridical experiences have some kind of mark that separates them from non-veridical experiences. Well, if you believe that, I have a nice bridge here in Brooklyn that I can sell you at a bargain price. The skeptic in these cases can always, properly, ask: how do you know that you are awake and not dreaming, or hallucinating? From the inside one sometimes cannot tell, which undermines the disjunctivist solution. Moreover, according to Hume, any attempt to justify knowledge by way of perception is doomed to failure. The notion that perception makes us directly aware of things in the world, or can somehow provide us with a mark of truth, as the Stoics thought, is “soon destroyed by the slightest philosophy” (Enquiry into Human Understanding, XII.18).
Externalism: Justification or knowledge can be grounded in a causal relationship holding between a given belief and the fact that such belief is about. For instance, I am justified in believing that someone is wet because they have just walked through the rain, and rain causes people to get wet. But this sidesteps the issue of how does one knows that such a causal relation exists in the first place. Remember Hume’s skepticism about the whole notion of causality!
Contextualism: Knowledge depends on context. When I say that someone is “tall,” for instance, this means different things depending on whether I’m referring to a child or to a basketball player. It follows that there cannot be a general, unqualified, skeptical challenge. All right, but this only establishes that our epistemic standards vary depending on the situation. Once we hold the situation fixed, however, and with it the corresponding epistemic standards, the skeptic challenge roars back with a vengeance.
Wittgenstein: Skepticism, according to Witty, is illegitimate because the skeptics don’t play the same “language game” as the rest of us. That is, skeptics use words like “knowledge,” “justification,” and “truth” while adopting either different meanings or higher standards than are found in normal discourse. And yet, the skeptical challenge seems to be perfectly understandable, including to Wittgenstein himself, so the skeptic language game is close enough to ours for us to make sense of it. If so, Wittgenstein’s dismissal of it is way too quick.
Fallibilism: We don’t need absolute truths, only probable ones. If I see rain outside, this is sufficient evidence for the pragmatic decision of picking up an umbrella on my way out. I don’t need to be absolutely certain that it is raining, that I’m not hallucinating, that I’m not a brain in the vat, etc.. I actually think this is a viable option, but it casts things in terms of probabilities rather than certainties, which is compatible with the sort of Academic Skepticism championed by the likes of Carneades and Cicero.
Of course, a serious treatment of the above mentioned responses to skepticism—and of the skeptic’s counters—would require a lot more space. The interested reader will find just such a treatment in the last section of the volume edited by Machuca and Reed mentioned above. But however one slices it, there simply hasn’t been a good, satisfactory, convincing, and widely accepted rebuttal of the skeptical challenge. And I doubt one will emerge any time soon. Or ever.
I’ve been a skeptic, of one sort or another, for most of my life. And I’ve never understood why skepticism makes people so darn uncomfortable. I guess there is a widespread, though obviously not universal, human psychological preference for certainty. This is the case in philosophy, in science, and of course most especially in religion.
But people also realize that they have to have some decent reasons for their alleged truths. Even religions, after all, engage in apologetics, that is, in exercises of rational justification of their core beliefs.
That is why the skeptical challenge makes most people so uneasy. If Agrippa & co. are right, it turns out that there is no ultimate justification for anything. It follows that we ought to engage in a bit more intellectual humility, qualifying what we say, at least implicitly, with “it appears to me that…” We should also always be ready to change our mind about things because new evidence or arguments may shift the balance of probabilities away from what we thought we knew and toward something else.
Just imagine, for a moment, what the world would look like if we all practiced skepticism. We would be less confident of our own positions, be they about science, philosophy, politics, or religion. We would be more open to listen to others and to change our opinions accordingly. We would also be less prone to impose our view of the world on others. And what, exactly, would be so bad about all of that? Skepticism isn’t something to endure, to accept with regret because there are no viable alternatives. It is, rather, something to embrace and celebrate because of its liberating power. As the famous 20th century lawyer and civil rights advocate Clarence Darrow aptly put it:
“Skepticism and doubt lead to study and investigation, and investigation is the beginning of wisdom.” (Why I Am An Agnostic, 1929)
Who’s afraid of skepticism?
Encyclopedic! Fascinating!
I think Descartes actually said “I think therefore I am”, not the other way round which would imply some sort of panpsychism, I think. 😃
Anyway, more substantially, this quote from Feynman is relevant to this post:
I think it's much more interesting to live not knowing than to have answers which might be wrong. I have approximate answers and possible beliefs and different degrees of uncertainty about different things, but I am not absolutely sure of anything and there are many things I don't know anything about, such as whether it means anything to ask why we're here. I don't have to know an answer. I don't feel frightened not knowing things, by being lost in a mysterious universe without any purpose, which is the way it really is as far as I can tell.