Glib remarks about taking things seriously

Thu 01 Nov 2007 04:36 PM

Andre Kukla* insists,

surely we must agree to the following principle: if there is some chance that we will have to take a claim seriously in the future, then we already have to take it seriously now, albeit perhaps not as seriously.
This principle is offered without argument, and Kukla seems to suppose that it is intuitively obvious. I have been at this long enough that my intuitions might be idiosynchratic, so I asked students. Some found it congenial and others were hostile, none thought that it was an uncontentious principle to which we must agree.

Consider two scenarios:

1. Thomas is a hacker who believes he lives in New York and not in a computer simulation. As such, he does not think that it is possible for anyone to perform anti-gravity kung fu. If Thomas were liberated from a computer simulation and introduced to a team of robot-fighting misfits, however, he would take the possibility of anti-gravity kung fu seriously. Therefore (by Kukla's principle) we must take the possibility of anti-gravity kung fu at least a little bit seriously.

2. Peter is a college student who believes in ordinary physics and does not think that a human body could exert the proportional strength of a spider without tearing apart. If he were bitten by a radioactive spider and gained stranger powers, however, he would take that possibility seriously. So (by Kukla's principle) we must take the possibility of spider powers at least a little bit seriously.

Enumerating scenarios of this kind is child's play. Perhaps they are a reductio of Kukla's principle. Or perhaps they show how science fiction and comic book fandom perform a service to the scientific community: Taking exotic claims a little bit seriously.

Of course, these conclusions require an uncharitable reading of what "some chance" means in the principle. I began this post thinking that I had a good deal more to say, how the principle comes out given various senses of possibility. I also planned to discuss a principle that Kyle Stanford appeals to at key moments, which is rather similar to Kukla's. However, I am now stymied by this: Is there any difference between the possibility that we will have to take a claim seriously in the future and the possibility that the claim might be true?

* 'Does Every Theory Have Empirically Equivalent Rivals?', Erkenntnis, 44:2. mar 1996, p. 150.