[moderator's note: This discussion began as part of the thread What Is Logic?, but was subsequently split off into this thread.] I think you might allow that there is an important difference between a concept, and that which a concept supposedly represents. Since we are discussing things at an empirically-oriented site, I'd say the prevailing theory here regarding that is correspondence; that is, we aim for our concepts to correspond to something that actually exists in reality. How do we find that out? Well that's where the empirical predilection shows up (i.e., more here, than say at a more rationalistic philosophy site) since we want to know how much what's been hypothesized to exist has been experienced. The reason I am bringing this up is to set up my challenge to something you've claimed, which I'll explain below. First, you say we know what existence is. Okay, how? Do you believe we know existence first and foremost through experience, or do you believe we can we know the existence of something by reason alone? Some things you've said in earlier posts led me to believe the former, but if you do believe it then I want to dispute the following: I say you cannot empirically prove God does not exist, and a purely logical proof (i.e., devoid of facts) is no proof at all (actually, it's not just God, you can't prove that anything doesn't exist . . . you can only prove something does exist). We cannot ever have sufficient evidence to prove God does not exist since God might exist somewhere or in some condition that evidence can't be obtained; and lack of evidence is not proof. That is obviously not an empirical proof, and neither is it a logical proof even if we accept all your assumptions (and you must know that you cannot prove your assumptions). You are assuming a priori truths, but I don't think, for example, it is self-evident that all things with identity have "definite qualities and quantities." What if it is our own conscious limitations that can't understand an indefinite identity, and so we project our inadequacy onto God? There is, in fact, a variety of inner practitioner who claims it is precisely the effort of the intellect trying to define God that makes God inaccessible because God can only be directly experienced. How about this one, what if God is generally indefinite, but becomes defined at times, such as to create a universe? If we throw out all our preconceptions about God, we might say something like: Because we know creation exists where once it didn’t (or so experts believe), we also know something brought about creation. We can logically infer too that whatever created the universe and its contents had to have been there before the creation it generated. So a flexible definition might explain the “creator” as whatever it is that has brought about creation. With that definition we have not, in advance, decided the creator must be a certain way. The creator may be nothing but physical processes, as physicalists believe, or the creator could be somehow conscious as many of the religious believe, or the creator might be a combination of things known, believed and as yet unimagined. Now, if God is the name we give the potentiality out of which all extant things arise, that potentiality just might be all the power there is, all the knowing (or knowing potential) there is, infinitely extended, eternally existent, etc. I think the best you can do with your "proof" (which would be made significantly stronger by adding all the empirical facts we have about how reality works) is to show an omniscient, omnipotent, etc. God of the sort proposed by creationists is implausible. Your statements do not rise to the level of proof unless one wants to put blinders on to all the possible ways one can get around your assumptions. P.S. If you meant to illustrate that "One can prove that God does not exist quite easily" within the context of Aristotle's Laws of Thought . . . never mind.