uwot wrote: ↑Tue Jul 11, 2017 9:06 pm
Immanuel Can wrote: ↑Tue Jul 11, 2017 8:25 pmWhat you need is an example of something like a "married bachelor" or "square circle" that exists in reality. Those would be verifiably conceptually incoherent.
Someone say 'Double Slit Experiment' to this idiot.
Based on what he has written, I Can’s definition of “conceptually incoherent” is synonymous with “logically impossible.” Nothing in the two-slit experiment entails any logical impossibility, so this would not fit his criterion. Two-slit just shows that the universe is really,
really weird — much weirder than we had ever suspected. It also shows we don’t really grasp the ontology of the universe — whether it is collapse or no-collapse. It can’t be both, but we have no empirical way currently to decide between these two interpretations.
I Can would do well to really study modal logic — because it could actually help at least some of his arguments.
Modal logic deals with possible worlds, which means
logically possible worlds. On this account, flying pigs and talking donkeys exist at some possible worlds — just not at the
actual world. But these are examples of “conceptually coherent” concepts that fail to exist. (Some might argue that flying pigs and talking donkeys are in fact not conceptually coherent in virtue of the fact that pigs cannot fly and donkeys cannot talk
by definition. Modal logic uses
counterpart theory deal with this kind of objection, but it would be a digression to go into this.
When we put aside Plantinga’s obviously bogus modal ontological argument, valid modal ontological arguments like that produced by Kurt Godel essentially clarify St. Anselm’s argument by showing that if God exists, he necessarily exists; but of course this offers no argument as to the “if” — as to whether God in fact exists. Nevertheless, such arguments conceptually clarify what Anselm was getting at, which I think theists should like even if they don’t get quite the result they wanted.
But modal logic can show other fascinating and unexpected things — a proof against the atheistic argument, as I discussed in the free will/determinism thread, that God’s infallible foreknowledge of all future contingent events forecloses human free will. Modal logic shows that God’s foreknowledge and human freedom are fully compatible, and thus is a defeater for the long-time atheist arguments to the contrary. Indeed, modal logic also supplies a solution to Newcomb’s Paradox. Willian Lane Craig, a theist philosopher, discusses this at great length.
With respect to the “conceptual coherence” of a “supreme being,” this is going to depend on how one defines “supreme” and “being.” I think that the traditional Christian concept of God entails at least one logical impossibility, which means such a being cannot exist at any possible world (i.e., is necessarily non-existent).