Re Plato on a priori/posteriori
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I have one question concerning Plato's theory of knowledge. I
understand that he believed in a priori knowledge, but is that
absolute. I mean, does Plato
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Plato of course would acknowledge that we have knowledge of
things based on sense perception, at least in the ordinary
English sense of the term 'knowledge'. (So in this sense he would
acknowledge that we have a posteriori knowledge.) In this sense
of course I know that now I'm sitting in front of my computer,
typing this message. However, in a much stricter sense, Plato
would call 'knowledge' only that sort of knowledge which is
necessary, and which therefore has to concern things that cannot
possibly be otherwise than they are. In this strict sense my
awareness of the fact that now I'm actually typing is not
knowledge, because of course this might be otherwise: I might as
well not be typing this message, but be with my family instead
(oh, well, but duty first ...:-). On the other hand, the truths
of geometry, arithmetic, logic, or the knowledge that true virtue
is a sort of wisdom, or that what is good is desirable, etc., in
general, a priori truths, are precisely such necessary truths
which concern things that cannot be otherwise, and thus such
truths are knowable also in Plato's strict sense of 'knowledge'.
According to Plato, the direct objects of this strict sort of
knowledge are the unchangeable, eternal, perfect ideas. So no
wonder he says that it is primarily this kind of knowledge that
we should strive for, which puts us in touch again with that
perfect realm of being where our souls really belong.