Tuesday, August 23, 2005

Rationality More Generally

Rationality seems to come in different stripes - familiarly, there are epistemic and practical notions of rationality. Maybe there are other (more specific?) kinds as well.

It would be nice to have a general notion of rationality that would cover all the cases. How about something like this:

R: An act’s rationality-of-kind-K is determined by the extent to which it promotes the aims which that act has in virtue of being a (certain type of) act of kind K.

For example, we might say that:

RE: A belief's epistemic rationality is determined by the extent to which it promotes the aims which that act has in virtue of being an epistemic act (or perhaps, more specifically, a belief-like epistemic act).

To get an idea of what I mean, suppose you think that the sole constitutive aim of an epistemic act is to do what will probably get you to the truth about the matter under consideration (so that any act that lacks this aim just isn't a belief). Then you'll think that a belief's epistemic rationality is determined by the extent to which adopting that belief is the (a) thing that will probably get you to the truth about the matter under consideration.

I take it RE would explain why it doesn't seem right to assess non-epistemic acts for epistemic rationality.

2 comments:

Jacob B said...

The account of rationality that you suggest there is sort of reminiscent of (of what would be the positive equivalent) of van fraassen's notion of irrationality. I think it goes something like this: One is irrational if one needlessly sabotages ones means of vindication. . and for reasonableness:As van Fraassen ([1989], 157) puts it:

a minimal criterion for reasonableness is that you should not sabotage your possibilities of vindication beforehand.

Don't know what you think about that, but it is an idea

Carrie Jenkins said...

Hi Jacob,

Thanks for the comment. As I understand it, van F is here just giving a *sufficient* condition for irrationality (one which is supposed to show why e.g. allowing a Dutch Book to be made against you is irrational). That transmutes into a *necessary* condition for rationality (we must not sabotage our possibilities of vindication beforehand). I was going for a full-blown account of what determines how rational something is, so I need to do a bit more than just give a necessary condition for rationality.

There could certainly be some points of connection though. If 'sabotaging your chances of vindication' means that there's no possibility of promoting the aims the act has in virtue of being the kind of act it is, then sabotaging one's chances in this way makes for irrationality by the lights of my principle R.