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Monday, February 20, 2006

Boghossian on the Compatibility of the First-person Knowledge and Content Externalism

I plan to write about (in)compatibility of the First-person knowledge and Content Externalism. As I understand, it is a worry of philosophers that the privileged status of the first-person knowledge seems to conflict with the main idea of content externalism. (So, e.g., when I sincerely utter, “water is wet,” I might not know that the content of my thinking was not: that twater is wet. This appears to conflict with the idea that I must know the content of my own thinking.) Boghossian argues that the compatibility of the two will generate a very absurd result – i.e. if compatibilism is true, then we would be led to know a priori certain facts about the world (which is clearly a posteriori). And I want to block his argument. So here’s his argument.
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In his “What the Externalist Can Know A Priori” (1998), Boghossian says that a compatibilist (of the First-person knowledge and Content Externalism) is in a position to argue the following:

(1) If I have the concept water, then water exists.
(2) I have the concept water.
Therefore,
(3) Water exists.

According to Boghossian, if content externalism were true, then (1) is knowable a priori. Also, given the privileged status of the first-person, (2) is knowable a priori. From these, it follows that (3) is knowable a priori. [In arguing this, Boghossian holds that in a valid argument, the a priori knowability of the premises guarantees the a priori knowability of the conclusion.] However, (3) is clearly not knowable a priori. Thus, there is something wrong in the compatibilism.

Boghossian considers two routes of rejecting this argument. First, an externalist can argue that (the existence of) water is not required in order for one to obtain the concept water – thus (1) is not knowable a priori. Second, the externalist can argue that although (the existence of) water is required for one to obtain the concept water, that fact is not knowable a priori.

Admittedly (at least by Boghossian), the second route seems more promising. In taking this route, I would like to suggest two ways to show that (1) is not knowable a priori.

1. In order to know (1), I need to know (at least) both

(a) If I have a certain concept x, then the object(s) correlated with x (i.e. the extension of the term that expresses the concept x) exist(s).
and
(b) Water is correlated with the concept water.

Here, what I know a priori is only (a). I do not know (b) a priori; I know it a posteriori. As a result, I do not know (1) a priori.

2. It seems right to me to say that in holding content externalism, (the existence of) water is presupposed for one to obtain the concept water (rather than saying that in holding content externalism (the existence of) water is required for one to obtain the concept water). If the existence of water is merely presupposed, then the fact that water exists does not follow from the fact that I have the concept water. In other words, the externalist would not be committed to the claim that water exists from his holding that he has the concept water. Thus, an externalist need not take (1) as an a priori truth. For him, (1) is plainly false.

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To be honest, I do not know if 2 is the right way to go. More specifically, I do not know:

(i) whether or not in holding content externalism, (the existence of) water is presupposed (rather than required) for one to obtain the concept water,
and
(ii) whether or not the blue-colored sentence is correct,
and
(iii) if I am right about (i) and/or (ii), what would be the good strategies to show that (the existence of) water is merely presupposed (rather than required), and that the externalist would not be committed to the claim that water exists from his holding that he has the concept water.

So I will appreciate greatly if you guys can share some thoughts. The comments about my (poor) wording would be of great help as well.

4 Comments:

  • At 9:50 AM, Blogger Alex said…

    Hey Brocolli,

    I'm inclined to agree that both your [1] and [2] are plausible launching pads for attacking Boghossian's anti-externalist argument. I'm a bit confused, though, by how you defend them.

    [1]: You claim that if the externalist knows (b), then the externalist knows (b) only a posteriori. But presumably, she can be justified in truly believing (b) on the basis of whatever philosophical reasoning and internal facts about concept acquisition that lead the externalist to accept (a) a priori. So as long as we're not infallibists about justification, then, it seems that the externalist can know (b) on the basis of (a) as long (b) happens to be true.

    [2]: I'm confused by your distinction between x's being required for vs. presupposed by the concept of x. Here's my best reconstruction:

    - x is required by S's concept of x iff whenever S employs the concept of x at time t, then x necessarily exists.

    - x is presupposed by S's concept of x iff whenever S employs some concept of x at t which was acquired at an earlier time t*, then x necessarily existed at t*.

    Is this what you mean by the distinction? If so, I'm not sure it is much help to the externalist. Even if employing the concept of x in thought merely presupposes that x existed at an earlier time, to know this historical fact is still to a fact about the external world on the basis of a priori grounds.
    This is, perhaps, less absurd than Boghossian's intended conclusion, but still deeply problematic for the externalist to accept.

    Cheers,
    --
    Alex S.

     
  • At 4:55 PM, Blogger Huiyuhl Yi said…

    Thank you vert much for your comments, Alex. There are something that I newly learned about my claims.

    First of all, I was wrong in saying that I can know (a) a priori. Now it seems that (a) is simply wrong. I have a concept of unicorn, as most English speakers do, but it doesn't entail that unicorns exist. Another counterexample: ancient physicists had the concept of phlogiston, but it doesn't entail the existence of phlogiston (at that time). These counterexamples (I learned them from Brueckner), I think, can also be used to show that (1) is not knowable a priori (since (1) is simply wrong).

    Also, I agree that I need to specify what I mean by presupposing. I also agree that defining it in terms of previous existence wouldn't help. I somehow thought that I could show: by presupposing x, one can avoid committing oneself to the existence x. I now am dubious about this approach.

     
  • At 10:11 PM, Blogger douglys said…

    One way out of the reductio is to insist that (1) is conditional on water actually being a natural kind as in (1*). If this is all the externalist is committed to then there is no more reductio, since the fact that water is a natural kind cannot be known a priori (see Tye and McLaughlin 1998 for this kind of reply).

    1. If I am thinking that water is wet, then water exists.
    2. I am thinking that water is wet.
    3. Therefore, water exists.


    1*. {If water is a natural kind then}, if I am thinking that water is wet, then water exists.

     
  • At 1:11 AM, Blogger Exoire Elessar said…

    Hi,

    Do you think knowledge is a vice?

     

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