I was talking to Juan Comesaña about practical
rationality yesterday, and a family of puzzle cases came up about which we
couldn’t figure out what to say. So I thought I’d share them with you and see
if I could let you all figure out what my intuitions are, because right now I’m
not sure I can.

(By the way, much of the talking was done in
a mock interview, in which Juan looked pretty impressive. Anyone out there who’s
looking to hire a talented young epistemologist/ethicist should have his agent
on their speed dial. (Alert: strained American football analogy forthcoming.) Being
an epistemologist and an ethicist should be a natural combination, like being a
wide receiver and a cornerback. But for some reason it’s not only rare, the two
fields are put into two different groups, so departments usually have to fill
two lines to cover both needs. When roster space is tight, multi-skilled philosophers
should be more highly valued than they actually are. I don’t really mean to
compare Juan to Deion Sanders, but that’s just a limitation of my talent at
drawing analogies.)

Anyway, the examples. To get the framework
in place, imagine that you’re more or less a Humean about practical value. In
particular, you think that being practically rational means, most of the time, acting
so as to satisfy your preferences. But, you think, actions that you only
believe will lead to preference satisfaction because you hold irrational
beliefs are not practically rational. So in GOOD BEER I am practically
rational, in BAD BEER I am not.

GOOD BEER
I’m watching football, and I realise that I want a beer. I believe there is
beer in the fridge because I put some there not long ago. So I stroll out onto
the porch and get myself a beer.

BAD BEER
I’m watching football, and I realise that I want a beer. I believe there is
beer in the fridge, but only because I hope there’s beer in the fridge, and I
always believe the world is the way that I hope it is. So I stroll out onto the
porch to get myself a beer.

If you don’t agree with us about
those cases then either you disagree so deeply about practical rationality that
you’re not going to care much about the following examples, or you’ve got a
different concept in mind to the one we have. But I hope you can at least
imagine agreeing with us about those cases. If you do agree with us, then you’ll
probably agree that there are potentially difficult cases when a decision is
partially based on an irrational belief and partially on perfectly rational
beliefs. For instance, the following families of cases are troubling. (The
cases will be underdescribed because I’m interested in how intuitions vary as
we vary some of the parameters in them.)

BEER AND
SANDWICHES
I’m watching football, and I realise that I want a beer and a sandwich. I
believe that both are in the fridge, because I remember putting sandwiches in
there, and that there is beer in the fridge, but that’s only because I hope
there’s beer in the fridge, and I always believe the world is the way that I
hope it is. So I stroll out onto the porch to get myself a beer and a sandwich.

BEER AND COKE
I’m watching football, and I realise that I want either a beer or a Coke. For
some reason right now these are pretty good substitutes for each other for me
now. (If you can’t imagine this then substitute other products.) I believe that
both are in the fridge because I put some of each in there yesterday. So I
stroll out onto the porch and when I get there I decide I’d prefer a Coke so I
get one. But when I get back to the couch I’m a little upset, because I realise
I had just got myself a beer five minutes ago, and it isn’t finished yet, so I
could have had beer without moving too far from the couch.

I have my suspicions about what
my intuitions are in each (instance of each) case, but I’m sort of interested
in hearing what other people think before I post them, so maybe that will be
left until later today.