BOO KS
305
show to their best advantage. It is a superb review of some of the most
significant results of this century in one of the few fields of philosophy
where hard results have been forthcoming. Not that the success of logic
need be considered to downgrade any other part of philosophy, or–
dinary-language analysis included; it is just that Austin's protest cuts
both ways. And it is well for logicians to remember that their own
work is embedded in ordinary language and common sense.
As far as that goes, Quine himself is not averse to common sense
even as a tool in logic. One of the popular paradoxes which recurs in
the literature (most recently in
Mind,
January, 1967) is that of the
Unexpected Execution. The judge announces to the prisoner on Sunday
that at noon on some day in the following week he will be hanged, but
that he
will
not know on the fatal morning whether or not his last day
has come. The prisoner argues that if he is still alive on Saturday
morning he will know he is to be executed that day, since it is the
last possibility; but that violates the second condition, so he eliminates
Saturday. Once Saturday is out, a similar argument disposes of Friday,
and so on back through the week. The prisoner congratulates himself at
having caught the judge in an inconsistency, but when the hangman
arrives on Thursday he is surprised after all and the judge is vindicated.
Quine'S solution to this paradox is to point out, in effect, that so far as
the prisoner knows the judge might have been bluffing all along; the
prisoner's uncertainty extends to the question whether he will be hanged
at all, and
a fortiori
to the question whether it will be on a given day.
It
is clear from this that logic is not a guide to life, but then Quine has
never maintained that it was.
It
is a powerful adjunct to empirical
inquiry, whose proper use requires prior discipline; its virtue lies in
the fact that if we supply it with truth, it will never yield falsehood.
Few men have shown the manner of its use with more authority.
Peter Caws
