Response to a question from Aretosis about doxastic causal closure

The original question was:

Would [doxastic causal closure] mean x believes y is good because [it] would benefit them would not be a reason for x believing y is good?

And the example he gave was:

I think reading is good because it helps me get knowledge

So this is what I came up with, I’m not trying to be overly wordy or unnecessarily complicated…I had to really think this through and I really appreciate the question. Hope this clarifies things.

There is someone who believes that reading is good.

Letting G stand for the proposition ‘reading is good’, we could put it this way:

S believes G.

Assuming this is really what S believes viz. G, I think we can infer at least a few other beliefs which S necessarily holds.

Further beliefs implied by believing G:

1. Some (but not all) things are good things;

2. It is possible to know which things are good and which are not (e.g., there is some bar which something must meet in order to count as ‘good’);

3. There exists some activity to which to the term ‘reading’ refers;

4. This activity meets whatever bar there is for something to count as ‘good’

I don’t see how S could deny any of these other claims while also holding to the claim that ‘reading is good’, and let’s assume S does in fact agree with them.

What follow-up questions might we ask of S?

Of all these other implicit beliefs, which is the most likely to elicit further questions? I’d submit #2 (at least, the parenthetical) and #4. We could start with either, but let’s say begin with #4 — we ask S, “What is it about ‘reading’ that makes it ‘good’?” (After all, his answer will probably tell us something about what he thinks makes something good, so we can knock over two pins at once). And, let’s say, S responds: “Reading is good because it helps me get knowledge”.

So now we’re dealing with three distinct claims (or, since they are claims that S assents to, three distinct beliefs).

• “Reading is good” (which we already unpacked above),

• “Reading helps me get knowledge”,

• “Reading is good because it helps me get knowledge”.

We can let K = Reading helps me get knowledge, and R = Reading is good because it helps me get knowledge (or, to put in the form of a conditional, ‘If reading is good, then reading helps me get knowledge).

Behind both K and R, there are a number of implicit ideas (some of which would carry over from G, so I won’t repeat those here).

Implicit in K:

• Some things get me knowledge

• Reading is one of those things

Implicit in R:

• Things that get me knowledge are things that are good¹

Now let’s return to the original question.

To paraphrase just a bit here for ease of understanding, Aretosis’ question was “Under doxastic causal closure, is S believing something is good because it would benefit them not a reason for S to believe that the thing is good?” But here, we arrive at an additional, distinct claim that S believes (and therefore, an additional set of implicit beliefs that believing this new claim would carry — the question, then, is whether one of those implicit beliefs includes R.

Let me try another way of explaining it, becuase I’m not sure if it’s clear.²

Suppose S were to claim that he believes ‘reading is good’ because he believes that believing ‘reading is good’ would benefit him in some way (e.g., ‘Other people would respect me if I believed that reading was good’). That would be an entirely separate claim (an entirely different belief that S holds) from any of the other three we’ve identified.

That claim is, to put it one way: If I believe reading is good, then people will respect me.

We could let B stand for this new, fourth claim that S believes. And, since we saw above how beliefs can carry other implicit beliefs, we should ask the same of this new one. The question then becomes: In the case of believing B, must S necessarily also believe R?³

Must S believe R to believe B? (In other words, is believing B a cause of believing R?)

Remember we’re looking for whether an implicit belief carried by B includes R. To me, though, it seems like the only implicit beliefs that are necessary for S to believe B are:

• “Some beliefs garner respect from others”

• “R is one of those beliefs”.

Again, there could be other implicit beliefs (like the belief that there is such a thing called ‘respect’, that ‘others exist’, that ‘some things are beliefs’, that ‘R is a belief’…but I don’t think we need to go into all that here). The point is: I don’t see where S must also actually believe R in order to believe B; hence, I would not say that believing B is a cause of believing R.

Conclusion

Since it’s possible for S to believe B without believing R, I don’t think believing B can be a cause of believing R. And so, if it happens that S does believe both B and R, then the former is surely not the cause of the latter. In fact, S’ belief in both B and R will each have their own distinct cause.

1. There might be other criteria that S requires for something to count as ‘good’, but let’s imagine this is the only one just for simplicity’s sake.

2. Actually, what precedes this was the second attempt I made at explaining it, and the one that follows was my first attempt.

3. Perhaps it’s not clear at this point why this is the question I’d ask. If that’s the case, then maybe that’s something I should flesh out more clearly, although my hope at least would be that it becomes more obvious why I’d ask that question by the end of the piece. If not, maybe I should just come out and say this: I think I take after a difference-maker account of causation, such that C is a cause of E just in case without C occurring, E would not have occurred. Put another way: If E could occur without C occurring, then clearly C is not the difference-maker (and hence, not the cause of E).