[net.philosophy] certainly won't vs certainly can't -- quite comprehensible

unbent@ecsvax.UUCP (11/02/84)

Re: flairvax.803, wherein Baba writes:

>The question then becomes: What is the difference between an event that
>certainly *will* not happen and an event that certainly *can* not happen?

	Depends on how you're taking "certainly", doesn't it?  If you're
confusing it with "necessarily" -- something that people who run
predictability and determinism together tend to do -- then there isn't any
difference [unless you subscribe to a modal logic weaker than S4 -- but
let's ignore the subtleties of iterated modalities for now. ;-) ].  If,
however, you respect the difference between *epistemic* notions
(predictable, certain) and *ontological* notions (determined, necessary),
then the difference will be clear.  There are lots of contingent truths
about which I'm certain and plenty of necessary truths (e.g., mathematical
truths) which I may believe, but about which I'm quite uncertain.  [I gather
that even mathematicians are divided on the question of whether the truth of
the four-color theorem is now known with certainty.]


Yours for clearer concepts,       --Jay Rosenberg
				    Dept. of Philosophy
...mcnc!ecsvax!unbent		    Univ. of North Carolina
				    Chapel Hill, NC  27514