On 2 March 2015 at 12:08, meekerdb <[email protected]> wrote: > Until you reflect that logic is just about relations between concepts we > made up - so maybe "logically necessary" isn't so necessary after all. I > find it interesting that a lot of "logically necessary" truths were > contradicted by quantum mechanics: Nothing can be in two places at the same > time. Two things can't be in the same place at the same time. The truths > of arithmetic seem to me to be the same way. The number of letter in > "this" word plus the number of letters in "that" word is 10 because each > has 5 letters. Or is it only 5: t h i s a ? It depends on how you > conceptualize "letters"; are they marks on the paper or are those marks on > tokens of the Platonic letters? >
The truths you mention were hypotheses about the nature of the universe. I don't think QM contradicted any arithmetical truths (if there are such things). It just showed that some intuitions about the nature of the universe we inhabit were wrong. I don't agree with your "truths of arithmetic seem to be the same way" argument. At least, not as stated - the example with the letters is merely a matter of what you're counting - are you counting the total number of letters, or only how many different letters there are? You get two different results depending on which of those you choose, but you get the same result every time for a given choice. In other words, there's no space for contingency once you've properly defined the problem. Which means that the truth of the matter does in fact appear to be logically necessary, unlike the "truths" about the nature of the universe (well, until a better contradictory example comes along - any ideas?) -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
