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not go far enough. Ockham’s razor is usually regarded as a (or even as

) fundamental principle

of scientific

(Harman and Kulkarni 2012). Inference implies belief in what is inferred

and to believe a theory is to believe that it is

. So, unless one can, in turn, connect the ersatz

virtues with truth,

that the ersatz virtues point to the truth is tantamount to

, the undeniable epistemic sin of presuming that reality is the way one wishes it were. To

methodologically justify Ockham’s razor as a principle of inference, one must methodologically

connect Ockham’s systematic bias toward simplicity with finding the true theory.

So let us turn, resolutely, to methodological justifications of Ockham’s razor that are

clearly truth directed. For example, Bayesians argue that if you start out with a simplicity bias over

alternative theories, and you continually update by Bayesian conditioning, then your degree of

belief in the true theory will converge to 1 in the limit. Here is what that amounts to. Transport

yourself in imagination to a more bucolic place and time, when a common entertainment was to

shoot rusty cans off fence railings. Suppose that the cans are arranged in ascending order of

complexity (e.g., the labels get fancier). Suppose that one of the cans is nailed to the fence rail.

That is the true theory. Now shoot down the cans, one after another, in order of increasing

complexity, until you shoot the nailed can and it does not fall down (Earman 1992). Ockham’s

razor finds the truth in

rote sort of way.

the nailed can is hit, it is, indeed, the simplest

can remaining on the fence. But that is as vacuous a truism as saying that the thing you seek is

always in the last place you look! It hardly follows that the things you look for are always

you; neither does it follow that simplicity can

the truth. An alternative way to converge to

the truth is to start out with a very complex theory and then to drop it when the anticipated

complexity does not emerge after some long period of time. Historically, that has happened many

times. For example, classical electrodynamics implies that the absolute velocity of the Earth

through space has a causal role in the generation of electrical currents (Staley 2009). Repeated

failure to detect any such effect contributed to the rejection of classical electrodynamics. The

problem is not to show that Ockham’s razor is sufficient for finding the truth. The difficulty is to

show that it is

for finding the truth, or that it is, at least, better than

methods

like the one just described. And that is very hard to do without begging the question with a material

assumption that the truth is simple or probably simple.

Here is the crux of the puzzle surrounding Ockham’s razor. If you demand truth in the short run,

you need to posit a

between simplicity and truth, and then you can’t explain how it

works without begging the question with a metaphysical story that explains the short-run

correlation. At the other extreme, long-run, methodological convergence is too weak, because

lots of different biases would get you to the truth in the long run. One conception of success is

too strong to be feasible without magic or question-begging assumptions; the other conception of

success is so weak that it does not rule out any conclusions in the short run, however complex.

The obvious, Goldilocks moral is to seek an intermediate success concept. Here is an ancient

hint, from the

, circa 600

BCE

:

2