My recent post in defense of classical logic has received a kind response from Robert of Dubito Deus. While he certainly has some valid points, I do not think they’re particular relevant with regard to the objection that I had raised. I’ll quickly clarify and reinforce some of the points that I made earlier in hopes that we can come to an agreement.
“This is fine in a general sense, but as I have mentioned in my previous article, classical logic doesn’t always match up perfectly with reality (here I am taking metaphysics as a discipline to be something which attempts to describe the features of reality).”
I’d prefer to define metaphysics not as an attempt to “describe” but as an attempt to “study” being as being. It’s a subtle but substantial difference in definition. The attempt to describe features of reality is more appropriately left to those in the philosophy of language. Logic, on the other hand, is the practice of reasoning our thoughts about things in a proper structure or manner. There’s distinctions within each practice, but each one is ontologically dependent on being to be anything at all. As such, I’d argue that while metaphysics as a discipline does “describe” reality in effect, it is first and foremost a study of being.
“A third example is fuzzy logic. I’ll simply say this – I challenge Gil to solve the Sorites paradox using only classical logic.”
I do not think this is relevant because if you recall, I already admitted that “they’re useful for other purposes…and can provide the kind of distinction between ideas that we need”. Classical logic, like any other logic, is still conventional to some extent but it never is conventional to the point that it treats metaphysically necessary truths as false. I am only defending the methodology of classical logic, not its wholesale implementation of conventional rules and syntaxes. In other words, the law of non-contradiction ought not to be rejected by any form of logic if it is to be a proper (yet distinct) extension of metaphysics. I’ll admit that I am by no means a logician, but I am a metaphysician. Every discipline ought to work within the limits of what is metaphysically possible or actual, otherwise, it is completely absurd. Therefore, any form of logic that works as if this was false is already self-refuting and useless.
I know this is short, but hopefully this provides some helpful clarifications.



One Response to In Defense of Classical Logic (Continuation)
Robert May 14, 2012
Re metaphysics: I think we pretty much agree here. My definition was just a quick one.
In other words, the law of non-contradiction ought not to be rejected by any form of logic if it is to be a proper (yet distinct) extension of metaphysics.
I think we mostly agree here too. I’m not a dialetheist (the view that some contradictions actually obtain). I do think paraconsistent logic has its uses, but correctly explaining metaphysical issues or talking about “actual” reality are not among them.
Classical logic, like any other logic, is still conventional to some extent but it never is conventional to the point that it treats metaphysically necessary truths as false. I am only defending the methodology of classical logic, not its wholesale implementation of conventional rules and syntaxes.
Indeed – the criticisms of classical logic in my previous posts were aimed at the syntax etc., not the methodology.
I’ll admit that I am by no means a logician, but I am a metaphysician.
This brings up an interesting side topic that might do everyone good to examine – the issue of academic “bias”. The opposite applies to me – I am by no means a metaphysician, but I am a logician. I think most people (including myself of course) are sometimes guilty of favoring their preferred disciplines over others; I’ve seen several things that point to this. Here’s some links:
http://philpapers.org/surveys/results.pl
http://prosblogion.ektopos.com/archives/2012/02/one-of-the-stri.html
http://prosblogion.ektopos.com/archives/2012/02/results-of-the-.html
http://www.smbc-comics.com/?id=2556