This week I’m going to continue the discussion of “common sense” from two weeks ago. I think it’s an important discussion because an overreliance on the concept of “common sense” can be (and seems to have been repeatedly) used to challenge the value and viability not merely of “religion” but of philosophy itself. I’m going to assume that readers of this current post have read that previous post – but not that they have read the comments on it, which have been the most numerous of any post on this blog so far (a full hundred!)

In those comments I challenged Thill to define the term “reliable,” which he had previously introduced to the discussion. I structured the post around the term “reliable” because in Thill’s previous comment, it had been at the centre of his only serious response to the point that “common sense” can be wrong (as in the case of sunrise and sunset). He said: “The fact that it is not infallible does not support the conclusion that it is not reliable!” No doubt I should have probed the definition of “reliable” further in the post – examining what Thill could have meant by it; I did not. I tried to make up for that lack in a later comment, where I asked Thill to define “reliable.” Thill responded that the onus was on me to define “reliable” since I had advanced a thesis relating to it; but my supposed thesis was intended as a response to his own thesis about the reliability of common sense, a word which, again, he introduced to the discussion. So I noted that I am happy to drop the term from the discussion as long as he, too, is willing to refrain from using the term “reliable” to refer to the epistemological status of so-called common sense. (That also applies to the others, Jabali108 and Neocarvaka, who have been exalting “common sense” in recent discussions.)

If we drop “reliable,” where are we left? We have established that “common sense” is not infallible. And within this discussion we may no longer describe common sense as “reliable,” unless someone wishes to reopen that can of worms – and anyone who does so had better define “reliable” and be prepared to defend the definition. (I note that Thill did briefly identify “reliable” as meaning “not likely to be justified or true” – but as I noted here, he had earlier claimed that concepts of likeliness or probability do not apply to the kind of philosophical claims most at issue in these discussions, such as the Madhyamaka claim that the visible world is illusory.)

So is there any way that common sense differs from any other kind of belief? When we assert “common sense tells us that X,” do our listeners have any additional reason to believe this claim beyond the bare assertion of X?

It is in the following comment, I think, that Thill updates his position on such questions in a way that does not rely on “reliable”:

As I have made clear a couple of times, it is a mistake to think that all of common sense is infallible or none of it is. Some of it is infallible, e.g., fire burns unprotected human skin. Some of it is plausible belief, e.g., there will be sunrise tomorrow.
Plausibility, is of course, consistent with fallibility. It is plausible to believe that there will be sunrise tomorrow, but it is a fallible belief.

Here, some common sense is infallible, and some of it isn’t; the latter is merely plausible. “Plausible,” as I understand it, means that something appears on the surface to be true. And I have no beef with the latter; I don’t believe I have ever said that common sense (or even any portion of it) is implausible. But even the Mādhyamikas agree that common sense is plausible: the majority of common sense turns out on reflection to be false, but we believe it in the first place just because it is so plausible. So for them, the plausibility of common sense is exactly what’s wrong with it.

Now what of those parts of common sense that are not merely plausible but infallible? Thill does not tell us how we are to distinguish infallible common sense from merely plausible common sense. But clearly, this distinction cannot be made merely on the grounds that it is common sense; the fact that something is common sense does not itself make it infallible, it only makes it plausible. Rather, there must be some criterion according to which some kinds of common sense are determined to be infallible and others are not – and this criterion cannot be the fact that they are common sense, since it has been agreed that there are kinds of common sense which are not infallible. By itself, the fact that something is common sense (by Thill’s definition) tells only that it is plausible; and something which is merely plausible may well be false.

In sum, it does not seem that, even on Thill’s view as developed here, common sense qua common sense carries any epistemological weight beyond mere plausibility. There is some “extra-commonsensical” criterion or criteria according to which common sense may be judged infallible or not. Once we hear what that is, we can debate whether it is correct that this criterion allows us to declare certain beliefs infallible. Regardless: according to this quote here, certain kinds of common sense are proposed to be infallible; but it is not and cannot be the fact of their being common sense that makes them so.

So when Thill or others use a phrase of the form “common sense tells us that X” (as for example here), are we to understand this as meaning only “X is plausible”? Which is to say, “X appears true to the untrained eye, but could easily on further reflection prove to be false (unless established to be infallible by some separate criterion of infallibility)”? I focused before on the concept of reliability because Thill’s use of it seemed to imply something much more significant than this sort of plausibility. But if it is indeed the case that (for Thill and others who refer to common sense) the fact of something being common sense indicates merely that it is plausible in this sense, then I will cease criticizing the concept, for it turns out we have no significant disagreement on that score. We may move on to other matters.

I am very busy with work this week, and don’t expect to be able to respond to comments at the length and frequency I did with the previous post. But I will read them and think about them.