twobits wrote:You are describing observations mostly. And concluding that the observations can go no further than they are observed.
Observations? You mean |- P -> P or the truth table for P & Q gives a truth function TFFF. There are no observations that will contradict these. The only guy to seriously make an attempt to argue that logic derives from empirical observations was the empiricist JS Mills. But otherwise you are on your own on that one. |- P-> P, is a theorem meaning true on no assumption, meaning true prior to any empirical observations.
twobits wrote:Based on the criteria which judges what is "unsound"
Well as long as the premise is not itself a contradiction or an invalid argument then you have to step outside the logical argument and make an empirical observation to check whether your premise is true. A premise is just the starting assumption.
twobits wrote:I contend that it marks the ends of acceptable thought. Anything outside of it might be deemed nonsense or it might really be.
Okay then. What are we to do with |- P -> ~P. Which says on no assumptions it is valid to infer ~P as a consequence of P e.g. “it is always true that, when it is the case the cat is on the mat we can conclude it is not the case the cat is on the mat”. Sorry twobits that don’t fly. Is this really where you want to steer you argument?
twobits wrote:If they stand as only observations of the end of thought,
They are not observations they are formal, a priori, necessary limits of thought.
twobits wrote:then they really serve no purpose or necessity as a reference because thought will stop anyway.
Logic in that sense has no purpose. It just is. When we stop thinking then we are no longer confined by logic.
twobits wrote:Go ahead, "Choose any you think you can break " would be a moot question, of course, but so would "nonsense" because "nonsense" would not be possible.....unless, of course, there is some criteria established within the "rules" which make that judgment and really do not observe the end of thought but rather makes rules to limit it.
I think I see where you are going. But this is not about hegemony of certain logicians telling people this is the only way to think because "we say so". The pursuit of logic is to describe the laws of valid argument. By saying |-P -> ~P is invalid is not hubris, or imposing a subjective standard. If you wanted to invent a logic where such a rule was treated as valid, you can try, but you’d be fooling yourself. Some things cannot be made valid by dictum.
twobits wrote:But your limits of acceptible thought say, I presume, is that cannot be, or is not so, based on whatever criteria you accept as logic.
No. Many times have I said one these boards that I am an irrational atheist. And I say that because I’m aware of what counts as a valid argument and how far I can push my position before I start talking nonsense. However, your argument from spirit as I am currently understanding it does not work, and vainly throwing pebbles at what counts as a valid argument does not protect it.
twobits wrote:They are not universally accepted because of the subjective nature of it.
No. It is because there are technical differences. For instance second order predicate logic quantifies over predicates, so it is possible to write (Af).Fx. This is an extention of standard first order logic that only allows (Ax).Fx. There are technical reasons why quantification over a predicate is suspect. However, it is a play off between technically suspicious modifications against added expressiveness. Slightly different case for Modal logic but the same point can be made. New operators introduced that can be criticised, but bring a gain in expressiveness. But none of the extensions attempted ever want to say anything like |- P -> ~P, or |- P & ~P.
twobits wrote:FB wrote:If you have some new rule then you can call yourself an heretical logician. Maybe you need to sign up to a non standard logic.
But that would suggest, again, that logic has some subjectiveness to it. I beleive I have been told ad nauseum that is NOT subjective.
No. For the reason just given. Bottom line there is still plenty of unfinished business in logic. But that does not mean certain established principles are ever going to be withdrawn.
twobits wrote:have not evaded anything. I have been very clear in stating my position and why. But I notice when it gets read back to me it is nothing like what has been stated. Some rule of logic, not mine, seems to change the acceptability of it. Even you missed it, it appears. What rule keeps you from doing that?
Sorry twobits if I have missed anything. I don’t think you’ve been clear at all. McCulloch seems to be doing a good job of setting up a position for you. In fact I'm using Mcullochs interpolation to gain access to what you are saying, but I want to see it from you Not the McC. Also I started to read back. I did not have to go far to find this
twobits wrote:It appears the logic limits anything after that, since it has already established that God cannot be.
Well I’ve never claimed that. There is a difference between claiming “logic says there is no God” to the criticism that “twobits argument is not a logical inference”, or to claim that belief in God is not logical. There seems to be some confusion here.
