My account of inference (see “Inferring as a Way of Knowing”) involves rejecting the view that, when you infer, you come to believe your conclusion in part because you take your premises to support it. In other words, it involves rejecting the second clause of the increasingly well-known “Taking Condition”:

The Taking Condition: “[i]nferring necessarily involves the thinker taking his premises to support his conclusion and drawing his conclusion because of that fact” (Boghossian 2014: 5, his emphases).

It’s a familiar fact about inference that you can come to know your conclusion by inferring it from your premises only if you already know your premises. But the same thing is arguably true of the sorts of “takings” mentioned in the Taking Condition. That is, arguably, you can come to know your conclusion by inferring it from your premises only if you already know that your premises support your conclusion. In both cases, the qualifier “already” is important. Your knowledge of your premises needs to be prior to your knowledge of your conclusion; otherwise, your knowledge of your premises wouldn’t ground your knowledge of your conclusion. And similarly for your knowledge that your premises support your conclusion.

Part of the idea behind my account of inference is that the second of these claims––that you can come to know your conclusion by inferring it from your premises only if you already know that your premises support your conclusion––is questionable. In fact, my suggestion is that, in the fundamental case, your knowledge that your premises support your conclusion is posterior to your knowledge of your conclusion. (The same is not true of your knowledge of your premises.)

So the difference between the standard view (which accepts the Taking Condition) and my view might be put like this: On the standard view, your knowledge that your premises support your conclusion is both causally and epistemically prior to your knowledge of your conclusion. On my view, by contrast, your knowledge of your conclusion is both causally and epistemically prior to your knowledge that your premises support your conclusion.

It was recently suggested to me that the following example poses a challenge to my view.

Suppose that, in fact, <q> and <r> together support <p>. And suppose that there are two people who are similar in the following respects:

(i) both of them know both that q and that r;

(ii) both of them infer <p> from <q> and <r>.

But suppose they differ in the following respect: the first knows that <q> and <r> together support <p>, but the second merely believes this. More carefully, both of them “take” <q> and <r> together to support <p>, but only the first’s “taking” amounts to knowledge.

Plausibly,  the first person now knows that p, but the second does not––because she does not know (but merely believes) that her premises support her conclusion. The challenge, then, is to explain why the second person fails to know that p, without relying on the second clause of the Taking Condition, i.e., without relying on the idea that each subject’s “taking” is part of what grounds her conclusion-belief.

Now, I agree that I can’t meet this challenge. But I don’t think I need to. On my view, if (i) and (ii) are both true, the second person, despite merely believing that <q> and <r> together support <p>, does know the conclusion. She knows the conclusion because (i) she knew the premises, (ii) she inferred the conclusion from the premises, and (iii) if you infer something from something else you already know, you come to know it.

In other words, from my perspective, the challenge rests on the assumption that the second person’s “taking” is among the grounds of her conclusion-belief. And I reject that assumption. (To be sure, I haven’t here said why I reject it. But what I say below is part of that explanation.) So, from my perspective, there is no challenge.

This response is, I think, unlikely to persuade. Part of the reason (at least) has to do with the fact that, quite clearly, both subjects might plausibly “take” <q> and <r> together to support <p> before they perform the relevant inference. And that makes it odd to suppose, as I do, that those “takings” play no role in bringing about or grounding the subjects’ conclusion-beliefs. In particular, they surely could play such a role, even if they don’t always; and, when they do, the second subject surely won’t come to know her conclusion.

At this point, deep differences between my approach and the standard approach start to become relevant. I think it’s important to ask, at this point, how the first subject knows that <q> and <r> together support <p>, and why the second subject believes this (i.e., what grounds their respective beliefs). In particular, it’s important to ask: what’s the most basic way of coming to know such a thing? For our subjects might of course have learned that <q> and <r> together support <p> via testimony; but then we want to know how the testifiers came to know it.

Now, it seems tempting to say that the most fundamental way of coming to know that some propositions support another is by in some sense “seeing” that they do. But there’s the rub: how different is “seeing” that <q> and <r> together support <p> from inferring <p> from <q> and <r>? Well, there’s at least this difference: you can “see” that <q> and <r> together support <p> without coming to believe that p (for example, because you don’t believe both that q and that r). So “seeing” the support relation isn’t inferring. Granted. But still: does that make it different enough from inferring to do the work it needs to do here, in providing part of an account of inferring?

I don’t know how to make this thought fully precise, but it seems to me that “seeing” that <q> and <r> together support <p> involves the very same (causal-epistemic) connection between mental acts that’s involved in inferring. What’s different is just the mental acts. Let’s say that, in “seeing” that <q> and <r> together support <p>, you merely “entertain” the propositions that q, that r, and that p. Then the idea is that, in “seeing” what you see, your entertaining both that q and that r grounds your entertaining that p, in the same sense in which, in inferring <p> from <q> and <r>, your believing both that q and that r grounds your belief that p. If that’s right, then, whatever exactly this connection is, and whether it first comes into view in inferring or in merely entertaining, the connection itself is prior to your knowledge that q and r together support p. In other words: your performance of some kind of “inferential act” (as we might call it) grounds your knowledge that the premise-propositions support the conclusion-proposition––rather than the other way around. (Or, as I’ll put it in a moment: your conception of some kind of inferential act––and your conception of it as potentially knowledge-producing––grounds your knowledge that the premise-propositions support the conclusion-proposition.)

An important crutch for the standard view, then, is the idea that our knowledge of the logical relations between propositions is prior to our drawing of inferences. But I’m not convinced that this crutch can bear the weight it’s being asked to bear. For one thing, it’s not plausible that our knowledge of all of the evidential relations between propositions is prior to our drawing of inferences; and so the standard view is likely to run into problems when it comes time to explain material inferences (unless the plan is to deny that there are such things––but that, too, isn’t terribly plausible). More importantly, though, it’s not clear that our knowledge of even the purely (deductively) logical relations between propositions can be prior to our drawing of inferences. For that knowledge seems of necessity to derive from the performances of mental acts that are essentially inferential, even if we don’t want to treat them as full-blown inferences (because, for example, we take the latter always to begin from and conclude in belief).

To put it another way: to know that <q> and <r> together support <p> is to know that you could come to know that p by inferring it from <q> and <r>. This, however, is explain support relations between propositions in terms of inference. And that suggests that we should be dubious of the idea that inference can be explained in terms of support relations between propositions. And that provides some important motivation for the theory of inference I prefer.

(P.S. There’s more to be said about the example I discuss here, and I’ll return to it in another post.)

References

Boghossian, Paul. 2014. What is inference? Philosophical Studies 169: 1–18.