Rook takes Bishop, Angler takes Trout

Tue 25 Mar 2008 08:05 AM

In Epistemology and the Psychology of Human Judgment,* Michael Bishop and J.D. Trout argue that epistemology needs to be informed by empirical results about how humans actually reason. I am sympathetic with this approach, having myself advocated using a psychological hammer to crack a traditionally philosophical nut. Nevertheless, Bishop and Trout too often overreach.

In part this is a matter of rhetoric. They celebrate psychology without pausing too much to consider weaknesses in various lines of research, while denouncing epistemology sans psychology as bankrupt. They advocate combining the two without retreating from that assessment; in the conclusion they write, "Gin is better than vermouth, but they're still better together" [p. 154]. This is an odd metaphor, because gin is only better than vermouth to some tastes and for some purposes; vermouth is key to tomato sauces (where it releases alcohol soluble flavors) and cheese sauces (where it stops long strands from forming). Regardless, lines like that occur throughout the book. They aim to be glib, and they hit a bullseye.

This fresh enthusiasm for empirical results contra the epistemological tradition elides deep problems with their own approach. They advocate what they call 'strategic reliabilism': We ought to engage in whichever reasoning strategy best balances high yield of true beliefs with low cognitive demands; that is, we want to believe true things, but we don't want to think too hard. Of course, this cost-benefit calculation can't be done from the armchair. It is an empirical question as to which strategy best balances these desiderata. Part of the problem, however, is that the truth desideratum isn't just a passion for truth simpliciter. What we want is significant truth.

They discuss this point in a breezy ten-page chapter, but it's mostly just bravado. Many truths are significant because they give us power to do what we want to do. We have prudential reasons for wanting those truths. Since those truths will all be hypothetical imperatives, then their account would just be a kind of vulgar pragmatism if that were all of 'significance'. They avoid that outcome by insisting that some things are objectively significant; for example:

We take it that discovering the truth about the physical or social structure of the world is intrinsically valuable. So even if we can't be sure that it will lead to any practical results, the physicists at CERN and Fermilab have epistemic reasons (beyond their prudential reasons) for spending cognitive resources on trying to discover the Higgs boson. [p. 97]

This is a natural enough thing to say, even though it's wrong.

The point is not even that it's wrong. My writing on the subject all came too late, and I won't fault them for failing to anticipate me.** But they had read Philip Kitcher's Science, Truth, and Democracy, in which he attacks the natural but wrong position.*** Bishop and Trout cite parts of STD approvingly when it suits them to do so, and the core of Kitcher's book is the attack on the notion of objective epistemic significance. They could not have just overlooked it.

It's the 21st-century now, and you can't naïvely rely on two sentences about objective significance when significant truth is a lynchpin of your would-be new paradigm.

* Oxford University Press, 2005. Amazon link

** See variously an excerpt of an old paper, more blogging, the bits on the function of science in my d-cog paper, and this recent draft.

*** Oxford University Press, 2001. Amazon link