The problem with empiricism is that we can always doubt the reliability our cognitive faculties vis-a-vis Cartesian worries. Say that God reveals Himself to you and only you. Might you not think to yourself that you have simply suffered from an illusion wrought by a "chemical imbalance" or some such occurrence? On the other hand, the deliverance of reason is dependable whether the external world exists or not.
Ahhh....well, I don't think reason can ever determine the nature or existence of a being. In a strict sense, nothing can. But I discard solipsism as useless. And I trust in my own sanity. My wife accuses me of being 'too sane'.
(She works in mental health)
Worthy of note, however, is that modal logic, like mathematics and other branches of logic, isn't "invented" for that implies that it is a mere convention which could have turned out to be some other way. Rather, modal logic, like mathematics and other branches of logic, is discovered. We didn't "invent," for example, that 2 + 2 = 4. We discovered such truth.
All things discovered must be interpreted and applied. There is nothing that precludes the possibility that our understanding of modal logic is flawed. IN any case, as previously stated, I see it useful only in testing the rationality of a position, not in establishing it as factual.
Hmmm...I'm not sure how to explain it. Basically, I see some flaws in the argument, in terms of it describing anything more than the rational possibility of a supreme being based on logical deduction. That, in and of itself, is not enough to effect my beliefs or behaviour in any sense, since I never precluded such a being in the first place. At times I wondered if this made the most appropriate tag for me 'agnostic' rather than 'atheist', but the tags themselves are pretty uninteresting and uninformative.
Suffice to say I find a God unlikely, and I find a God as described in any Earthly religion more unlikely. But, clearly, some people will use arguments such as this to 'logically deduce' that their particular flavour of God exists.
Deep theological and philosophical musings evade me at present,
I'm a pretty simple guy at heart, so best to tailor the message accordingly...
so allow me to just consider this banally: say that there is an ultimate source of all being -- indeed being itself, according to Aquinas -- who is all-powerful, who exists necessarily, who is perfect, who is omniscient, etc. Doesn't this by itself illicit worship? Now consider further that this ultimate source of being decided to create everything else that exists, either directly or indirectly, including the universe we inhabit and ourselves and all our loved ones and the He has decisively revealed Himself to us in various ways. Doesn't this just add warrant for worship of such being?
Frankly, no. Even assuming a propensity to worship anything (and for the sake of argument, let's call it 'show a high level of respect') I would need to have some understanding of it and it's motives. Why would such a being care in the least as to whether I worshiped it or not? It understands my motives better than I understand them myself, so I would have no need to fear it (if indeed your logical deduction about omnibenevolence are remotely accurate).
I would enthusiastically recommend The Last Superstition: A Refutation of the New Atheism by Edward Feser. He writes from an Aristotelian-Thomistic perspective and his book is extremely rewarding to read through. I must mention that this particular book of his is markedly polemical, but it is unfailingly appropriate and satisfying and directed almost exclusively at the intellectual buffoonery of non-philosophers like Richard Dawkins, Christopher Hitchens et al. who think they speak with authority on a subject they have no authority on (i.e. philosophy). It can also be a challenging read generally, especially when he explains and introduces to the reader the Aristotelian-Thomisitc metaphysical apparatus. On a personal note, this book of his was decisive in my commitment to theism.
Hmmm...okay. If that's your suggestion, I'll try and hunt it up at some point pre-Christmas. Gotta say that generically I find philosophy a stretch. It's not that there is no interest, but (as stated before) I'm a reasonably concrete guy, and haven't read enough philosophy to have a really good grounding. History is more my thing, I suppose, with a smattering of just about everything else (including philosophy). We'll see how I go, I suppose.