In each hand, you hold a hammer. As far as their intrinsic qualities are concerned, the two hammers are indistinguishable. Hence, they would seem to be equally useful for doing things like pounding in nails, tearing down walls, and “fixing” crashed Macintosh computers. However, the hammers do differ in one respect: the hammer in your right hand belongs to you, the hammer in your left hand belongs to a neighbor, who has explicitly told you that you may not use his hammer. Here, then, is a question:
Is the hammer in your right hand more useful (to you) than the hammer in your left hand?
I claim the answer is ‘yes’. But I do not wish to disagree with you if you say that there is a sense in which they are equally useful. I only wish to claim that there is a sense in which the hammer in your right hand–the one that you have the right to use–is more useful than the hammer in your left hand. Let us call the sense of ‘useful’ according to which the hammer in your right is more useful than the hammer in your left ‘instrumental-cum-normative usefulness’. And, if you believe there is such a thing, we can call the sense of ‘useful’ according to which the two hammers are equally useful ‘pure instrumental usefulness’.
That’s enough about hammers. What about true beliefs? You and I both truly believe that P. Also, let us assume that in each of our cases, our true belief that P is useful–suppose, for example, that each of us wants to get to Larissa, and P is the true proposition about how to get to Larissa. However, there is one important difference between us: your belief that P is justified and mine is not–suppose, for example, that you formed your belief on the basis of conclusive evidence and I formed my belief on the basis of a fortune cookie. Now I have a question:
Is your true belief that P more useful (to you) than my true belief that P (is to me).
As before, I claim the answer is ‘yes’, in the very sense that the hammer in your right hand is more useful than the hammer in your left: although our true beliefs that P might be equally useful in a sense–by acting on them, we will both get to Larissa–there is also a sense in which your true belief is more useful than mine. Having a true belief that P, I claim, does not automatically make it rational for one to act on the basis of one’s true belief that P. For if to be rational to let one’s true belief that P guide one’s action, one must have a justified true belief that P. Hence, it is rational for you to act on your true belief that P, but it is not rational for me to do so. Hence, you have the epistemic right to act on your belief–just as you have the right to use the hammer in your right hand–but I do not have the epistemic right to act on my belief–just as you do not have the right to use the hammer in your left hand. Hence, there is a sense in which your true belief that P is more useful than my true belief that P: it is more pragmatic-cum-normatively useful.
Note 1. Notice that on the above account, the value of a justified true belief is not merely the value of a true belief plus the intrinsic value of a justified belief (if there is such a thing). The value of justification, on the above account, is extrinsic, because it’s value is essentially tied to the value of getting what you want–for example, getting to Larissa. This of course allows that justification might also be intrinsically valuable.
Note 2. Assuming Gettier was right, the above account does not account for the distinctive value of knowledge–that is, it does not account for the alleged fact that knowledge is more valuable than any proper subset of its constituents. In fact, I reject that claim. However, I do think that knowledge is more valuable than mere true belief, and, assuming that knowledge is at least justified true belief, the above account does account for the fact that knowledge is more valuable than mere true belief.
Note 3. I have assumed that true beliefs are valuable because acting on them will make you more likely to get what you want than acting on false beliefs. Where this assumption does not hold, the above account does not apply.
Note 4. Lately I’ve been perusing Jonathan Kvanvig’s The Value of Knowledge and the Pursuit of Understanding (2003). Kvanvig agrees that justified true belief is more valuable than mere true belief, but his account is, as far as I can tell, importantly different from the one I’ve presented here (see chapters 3 and 4). See also chapters 1 and 2 for a great discussion of the swamping problem for views that try to account for the value of knowledge/justified true belief over true belief in terms of objective likelihood of truth. The swamping problem is roughly that once a belief is assumed to be true, the value of a belief that is objectively likely to be true is completely swamped.
Note 5. This post was composed using Google Docs.