H. P. Grice's Crazy Bayesy

Grice explores an extreme scheme of "Crazy-Bayesy"
deliberation which rests on a mechanical model of the vectoring of
forces (with
desires -- or animal spirits -- as such drives).

In the scenario, R has two ends E1 & E2.

Each has a different degree of desirability: d1 and d2.

Now for any action A1 which will realise E1 or E2 -- to this or that
degree
-- there is a probability p1 that A1 will realise E1 & a probability p2
that A1 will realise E2.

The desirability of the action, relative to E1 & E2 is a function of the
desirabiity of E1 and E2 & the probability that A1 will realise E1 and
E2.
Only if A1 scores higher (in
action-desirability relative to E1) than any alternative action, should
R
should choose to do A1.

Provisions should be made for, e.g. long-term (standing) vs. situational
ends.

R may priorise family over business, and his children over Aunt Jemima
(who's been living with R all these years). On a particular occasion,
though, R
may priorise Aunt Jemima (to get her
out of one of her tantrums) over taking R's son to see the hippopotami
at
the zoo.

While prudential rationality is perhaps _not_ just means-end
rationality,
the determination over desires certainly does involve means-end
rationality.

But Grice allows that at Oxford most philosophers are too sensible to be crazy Bayesy.