10-04-2007, 09:42 AM
It is written, "Hear O Israel, the Lord our God is one Lord." Deut vi.4.
I answer that, It can be shown from 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 communicable only to one. Therefore, if Socrates were a man by what makes him to be this particular man, as there cannot be many Socrateses, 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. Therefore, in the very same way God is God and this God. It is impossible therefore that there should be many Gods.
Secondly, this is proved from the infinity of His perfection. For it was shown above that God comprehends in Himself the whole perfection of being. If, then, many gods existed, they would necessarily differ from each other. 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.
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 come together in the same order unless they are ordered thereto by some one being. For many are reduced into one order by one better than many: because one is the per se cause of one, and many are only the accidental 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 accidentally, it must be that the first which reduces all into one order should be only one. And this is God.
Since One is an undivided being, if anything is supremely one it must be supremely being and supremely undivided. Now both of these belong to God. For He is supremely being inasmuch as His being is not determined by any nature to which it is adjoined; since He is being itself, subsistent, absolutely undetermined. And He is supremely undivided inasmuch as He is divided neither actually nor potentially by any mode of division; since He is altogether simple, as was shown above. Hence it is manifest that God is ONE in the supreme degree.
From the Basic Writing of St. Thomas Aquinas
I answer that, It can be shown from 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 communicable only to one. Therefore, if Socrates were a man by what makes him to be this particular man, as there cannot be many Socrateses, 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. Therefore, in the very same way God is God and this God. It is impossible therefore that there should be many Gods.
Secondly, this is proved from the infinity of His perfection. For it was shown above that God comprehends in Himself the whole perfection of being. If, then, many gods existed, they would necessarily differ from each other. 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.
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 come together in the same order unless they are ordered thereto by some one being. For many are reduced into one order by one better than many: because one is the per se cause of one, and many are only the accidental 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 accidentally, it must be that the first which reduces all into one order should be only one. And this is God.
Since One is an undivided being, if anything is supremely one it must be supremely being and supremely undivided. Now both of these belong to God. For He is supremely being inasmuch as His being is not determined by any nature to which it is adjoined; since He is being itself, subsistent, absolutely undetermined. And He is supremely undivided inasmuch as He is divided neither actually nor potentially by any mode of division; since He is altogether simple, as was shown above. Hence it is manifest that God is ONE in the supreme degree.
From the Basic Writing of St. Thomas Aquinas