Aquinas wrote:I answer that, It can be shown from these three sources that God is one.
First from His simplicity. For it is manifest that the reason why any singular thing is "this particular thing" is because it cannot be communicated to many: since that whereby Socrates is a man, can be communicated to many; whereas, what makes him this particular man, is only communicable to one. Therefore, if Socrates were a man by what makes him to be this particular man, as there cannot be many Socrates, so there could not in that way be many men. Now this belongs to God alone; for God Himself is His own nature, as was shown above (3, 3). Therefore, in the very same way God is God, and He is this God. Impossible is it therefore that many Gods should exist.
Yes, Heavenly Father is "this particular God"--the only one with whom we have to do. But even the Bible proves that there are other beings called god (and no, I'm not going to quote 1 Corinthians 8:5. Try instead 2 Cor. 4:4 "In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them." You don't believe that Heavenly Father and Satan are the same god do you? Furthermore we learn that we are to be one with Jesus as He is one with the Father: "And the glory which thou gavest me I have given them; that they may be one, even as we are one:" (John 17:22)
"Mr. President" (the president of the United States of America) is a particular man (George W. Bush) and the only president of the US with whom we have to do. However, there have been many Mr. Presidents (of the USA) in the past and there will almost certainly be more in the future.
Aquinas wrote:Secondly, this is proved from the infinity of His perfection. For it was shown above (4, 2) that God comprehends in Himself the whole perfection of being. If then many gods existed, they would necessarily differ from each other. Something therefore would belong to one which did not belong to another. And if this were a privation, one of them would not be absolutely perfect; but if a perfection, one of them would be without it. So it is impossible for many gods to exist. Hence also the ancient philosophers, constrained as it were by truth, when they asserted an infinite principle, asserted likewise that there was only one such principle.
This from a world-renowned philosopher/theologian? What if they differ from each other only in location or their favorite color or some other trival matter? Do the differences have to be in perfection or privation? One can be distinguished by trivial differences (in my opinion that trivial difference would be location). Look, when we look at the atomic world, each electron is more or less indistinguishable from another other than properties such as present energy and spin. Yet each of those electrons are perfectly capable of changing their energy, spin or other properties. As far as being an electron goes, they do not lack any perfection of another. They are, in an important sense, equal.
Aquinas wrote:Thirdly, this is shown from the unity of the world. For all things that exist are seen to be ordered to each other since some serve others. But things that are diverse do not harmonize in the same order, unless they are ordered thereto by one. For many are reduced into one order by one better than by many: because one is the "per se" cause of one, and many are only the al cause of one, inasmuch as they are in some way one. Since therefore what is first is most perfect, and is so "per se" and not ally, it must be that the first which reduces all into one order should be only one. And this one is God.
First off, not everything needs to be ordered by something greater. I have a dual-core (multiprocessor) computer at home. Both cores are equal to each other--neither one orders the other around. Instead they communicate and cooridinate actions with each other through use of shared memory and concepts such as spinlocks, semaphores, mutexes, and the like. Now you may counter that they are following human instructions to coordinate their behavior and it is true. However, the humans that designed them also largely operate separately and equally, but coordinate their efforts through email, meetings, testing, and so on. But then perhaps you'll claim that there is a boss who has the final word. I disagree. The market has the final word. There is more than one OS maker and more than one CPU maker. The market choses who made the best decision by purchasing their products. The free market itself is an inherently distrubited decission making agent guided by nothing more than the "invisible hand".
But, you will claim, everything that exists has a cause. Well, welcome to the 21st century. Have you ever heard of quantum mechanics? It appearst that many events do not really have a cause. They just happen. See http://en.wikipedia.org/wiki/Quantum_fluctuation
Finally there need not be a first God. Tell me what the smallest positive rational number is. By the way, I'm not saying that I know for certain that there was a God before our Heavenly Father. I'm just criticising your proof of one God.