(March 17, 2017 at 9:23 pm)Nonpareil Wrote:(March 17, 2017 at 8:01 pm)RoadRunner79 Wrote:
By showing that it is a logically coherent definition with parameters that can actually be fulfilled.
It is quite possible, for example, to challenge the coherence (and, therefore, possibility) of a definition that is "omniscient, omnipotent, and 'wholly good'", as none of these concepts are particularly well-defined and the latter is completely nonsensical, as "goodness" is a value judgment and has no objective standard.
Even if you could demonstrate this, though, you would still have to demonstrate that it is possible for an entity with these characteristics to exist. You would, in fact, have to be able to show that the universe is logically compatible with the existence of a maximally excellent entity - but you don't know enough about the universe's characteristics to be able to argue that.
I'm afraid, that if you do not understand what "all knowing" or "all powerful" is, then I don't believe I can simplify those any more for you. As for goodness, that is an entirely different subject, and of much philosophical debate, so I'm not going to get into it and off topic (I think that most people in the end, act as if it is objective). But if you are saying that nothing is objectively greater than anything else, then I disagree and find it absurd. You are saying that knowledge is not greater than ignorance, and wisdom is not greater than foolishness. That these are incoherent statements correct? That these are just value judgements?
No. Again, even if the definition of "God" can be shown to be logically incoherent, it can only be shown to be so with respect to itself. It is not a matter of whether or not the definition is coherent; it is a matter of whether or not it is compatible with the definition of "universe".
This is where we get into the issue of S5 not necessarily being the appropriate set of axioms for Plantinga to use. It is the only axiom set which allows him to move from "possibly necessary" to "necessary", but the specific axiom set that you use is dependent on exactly what sense in which you mean "possible" or "necessary".
The two ways in which these can be used, for purposes of this argument are the epistemic and the metaphysical. Epistemic possibility has to do with whether the thing is actually possible in our world, while metaphysical possibility only cares about whether or not there is a logically coherent abstract world in which it could be true. S5 is a set of axioms specifically designed for use with epistemic statements, but Plantinga is asserting the metaphysical possibility of his necessary entity. Again, modal logic is not my particular area of expertise, but it is entirely possible that S5 does not apply, and that Plantinga should instead be working under, say, S4, which does not allow for the leap from "possibly necessary" to "necessary" - and if he is working under S5, then he still needs to establish that it is actually epistemically possible for this being to exist.
Correct me if I'm wrong, but you appear to be saying here, that under the axioms of S5, that it must be shown epistemically possible in the actual world. Now I'm just learning this stuff myself, but nothing I see, in the descriptions of S5 state this. Why have the semantics of other possible worlds at all, if this where true. Now in S5, the worlds must be relational, to my understanding means, that you cannot just apply another set of logically consistent but totally different set of physics. Now as discussed the argument does leave open the possibility that God is not logically possible. However as I stated; I tend to default to possible rather than impossible, if I do not find a reason to do so. Frankly, I think you are confusing metaphysical possibility with epistemic possibility with your last statement. This is showing that we can know through logic, without empirical evidence.
