Debunking Skepticism

Black sheep

I. The skepticism of philosophers

A mathematician, a scientist, an engineer, and a philosopher are sitting in a cafe in a foreign country. Outside the window, they see a black sheep in a field by itself.

The engineer says, "Well, what do you know? It looks like the sheep around here are black!"

The scientist gives him a skeptical look and says, "Well, at least some of them are."

The mathematician looks at the first two and says, "Well, at least one of them is."

Then the philosopher looks doubtfully at the other three and says, "Well, at least on one side."

As this joke illustrates, philosophy is the most skeptical discipline there is. Some skeptical arguments appeal to outlandish "skeptical scenarios," such as the brain-in-a-vat and deceiving God scenarios. Others propose some impossible condition on how one should acquire beliefs, such as completing an infinite chain of reasoning.

One type of skeptical argument has become especially popular lately: the "debunking" skeptical argument. This is a kind of argument in which the skeptic claims to have evidence that some interesting class of beliefs are explained by some factor that should not be expected to have any reliable connection to the truth. We are invited to conclude that those beliefs are probably not true, or at least that we don't know them to be true.

Example: some say that our moral beliefs are explained by the culture we happened to be born into, by our genes, or by personal biases. Therefore, either (i) there aren't any moral facts, or (ii) we don't know the moral facts. For present purposes, I count both (i) and (ii) as forms of "skepticism". Debunking skepticism is especially popular for morality and other norms.

II. Skepticism about skepticism

I am skeptical toward skepticism. In particular, I am a debunking skeptic about philosophical skepticism: I think the belief in philosophical skepticism, and especially moral skepticism, is best explained by factors that have no reliable connection to the truth. I think philosophers have a bias toward skepticism, and especially moral skepticism. We should therefore discount skeptical arguments from philosophers.

Why think the philosophical tendency toward skepticism is a bias?

1. Philosophy is an extremely skeptical discipline, more so than any other field.

2. There are two salient ways of explaining this:

   • (a) Skepticism is correct, and philosophers are more reliable than those in any other field; hence, philosophers are more likely to adopt skeptical stances.

   • (b) Philosophers are biased toward skepticism. Roughly, this means that some factor that is not a reliable truth-indicator inclines philosophers toward skepticism.

3. Explanation (a) is super implausible.

4. Explanation (b) is very plausible.

5. So it's probably that philosophers have a skeptical bias.

Now I'm going to say more about points (1), (3), and (4).

III. Philosophy is absurdly skeptical

It is not only morality that philosophers are skeptical of. Virtually everything that philosophers have discussed (and that includes almost everything) is something for which we have developed skeptical arguments. Whatever it is that you want to talk about, some philosopher is going to say (i) it doesn't exist, or all our substantive beliefs about it are false, or (ii) we can never know anything about it. Examples:

Topic : skeptical philosophical views about it
Physical reality : external world skepticism, idealism
Everything unobserved : inductive skepticism
Morality : moral skepticism, nihilism
Meaning : semantic nihilism, denial of meanings (Quine)
Truth : view that all or nearly all statements are false (Unger, Wheeler)
Personal identity : no-self view
Free choice : hard determinism, hard incompatibilism
The mind : eliminative materialism
Properties, abstract objects : nominalism
Practical reasons : normative nihilism
Epistemic reasons : radical global skepticism

All the above philosophical views have been held by respected philosophers. All are still taken seriously in the field today, with the possible exception of idealism--which, however, was the dominant view in the 19th century. Notice that nothing similar is true of any of the sciences. In scientific fields, no one denies the existence or knowability of the central objects of study. E.g., it is not a serious view in geology that the Earth doesn't exist, or rocks don't exist. It is not a serious view among biologists that nothing is alive, or that no one knows anything about life. You could not make a career in these fields out of defending such views.

Notice that moral skepticism is not an isolated example. Literally every single belief that anyone has falls under the scope of one or another skeptical philosophical argument, and one that has been seriously advanced by respected, professional philosophers.

Think you know an exception? "2+2=4", perhaps? Nope: https://plato.stanford.edu/entries/fictionalism-mathematics/. "I exist" then? No again: https://link.springer.com/chapter/10.1007/978-1-349-04862-5_10.

If there were skeptical arguments about just a few widely-held beliefs, it would perhaps make sense to review each skeptical argument on its own. But when the profession devises skeptical arguments about literally everything, then one has to think something very strange is going on, and we should take a step back and ask why we are so insanely skeptical.

IV. Philosophers are not specially reliable

Maybe what's going on is that philosophers are smart, open-minded, good reasoners, and generally good at getting to the truth, whereas other people are stuck in their benighted prejudices and so unable to appreciate the compelling case for skepticism.

Some of that is true: philosophers are, on average, smarter, more open-minded, and better at reasoning than non-philosophers. But the suggestion that philosophers are especially reliable--i.e., good at getting to the truth--strikes me as wildly implausible.

If philosophers were especially reliable, there are at least two things we would expect to see: (1) more progress in philosophy than other fields, (2) more agreement among philosophers than among those in other fields. Both of these are the opposite of what we see.

It is also intrinsically implausible (almost by definition implausible) that skepticism is generally correct. Prior to considering philosophical arguments, it seems extremely plausible that: the physical world exists, I have a mind, torturing babies for fun is wrong, 2+2=4, I exist, some people know things, and so on. Each of these propositions, I would say, I assign a near-100% prior probability. The prior probability of philosophers being biased toward skepticism is much higher than the prior probability of all these things being false. Therefore, the best explanation of philosophers having all these skeptical arguments is not that skepticism is correct; a better explanation is that philosophers are biased toward skepticism.

V. Skepticism plausibly results from bias

There are two important points here. One is that the type of arguments skeptics give are the type that are obviously susceptible to being influenced by bias. Skeptical arguments do not, for example, fall out of mathematical calculations, or scientific experiments, or deduction from direct observation (all methods that are resistant to bias). Rather, they turn on abstract, usually vague premises that have some sort of vague intuitive plausibility but are controversial in the field.

The other point is that it's easy to see reasons why someone might have biases toward skepticism. We might have an abnormal fear of being dupes. We might like the way in which skepticism relieves us of the obligation of figuring out difficult things and giving an account of them. Debunking the beliefs of others might make us feel clever and superior. Giving clever arguments for radically revisionary views also brings academic fame and professional rewards. In the case of morality, we might find its demands vexatious and seek escape in skepticism. Moral skepticism might fit with our preferred ideology--perhaps a politically-correct, cultural relativist ideology, or a science-worshiping ideology. And so on.

The point is, most forms of philosophical skepticism, especially including moral skepticism, are exactly the sort of thing that people would care enough about to be biased, and that at least some would be emotionally attracted to. They are not like most mathematical or scientific questions, about which most people have little feeling. For instance, if you want to figure out the melting point of iridium, you probably don't have to worry that personal biases are going to get in your way; the value of that melting point is not going to be a major point in anyone's ideology. Not so for philosophical skepticism.

VI. Debunking skepticism

Debunking skeptics (that is, those skeptics who seek to debunk our beliefs) argue that second-order reflection ought to convince us that our ordinary (e.g.) moral judgment faculties are unreliable. Once we realize this, the skeptics argue, we should set aside the beliefs that issue from those faculties, however plausible they might have seemed. Thus, say the skeptics, we should not use our ordinary moral intuition or moral reasoning to figure out whether nihilism is correct.

Following the same logic, we can engage in higher-order reflection on the way in which we arrive at skeptical philosophical beliefs, including reflection on whether the reasoning of philosophers is afflicted with a bias. If it independently seems likely that philosophical reasoning is affected by a skeptical bias, then we should not simply evaluate skepticism by directly assessing the skeptics' arguments; we should set aside those arguments because they are probably unreliable.

The effect of this is to return us to the state we were in before we encountered skeptical arguments--that is, for most, a return to common sense morality.

[This is based on a paper I have written for an anthology on Higher Order Evidence and Moral Epistemology (ed. Michael Klenk, Routledge, forthcoming). --mh]