Again, when you say,
“I grant you that you can't
know
when A has pain, you can only conjecture it”, you
don't see the difficulty which lies in the different uses
of the words “conjecturing” and
“knowing”. What sort of impossibility
were you referring to when you said you
couldn't
know? Weren't you thinking
to || of a case analogous to that
when one couldn't know whether the other man had a gold
tooth in his mouth because he had his mouth shut? Here
what you didn't know, you could nevertheless imagine to
know; it made sense to say that you saw that tooth although you
didn't see it; or rather, it makes sense to say that you
don't see his tooth and therefore it also makes sense to
say that you do. When on the other hand, you granted me
that a man can't
know whether the other person
has pain, you do not wish to say that as a matter of fact people
didn't know, but that it made no sense to say they knew
(and therefore no sense to say they don't
know). If therefore in this case you use the term
“conjecture” or “believe”, you
don't use it as opposed to
“know”. That is, you did not state that
knowing was a goal which you could not reach, and that you have to
be contented with conjecturing; rather, there is no goal in this
game. Just as when one says “You
can't count through the whole
90.
series of cardinal
numbers”, one doesn't state a fact about human
frailty but about a convention which we have made. Our
statement is not comparable, though always falsely compared, with
such a one as “it is impossible for a human being to
swim across the Atlantic”; but it
is analogous to a statement
like
“there is no goal in an endurance race”.
And this is one of the things which the person feels dimly who
is not satisfied with the explanation that though you
can't know … you can conjecture ….