Works of St. Anselm, tr. by Sidney Norton Deane, [1903], at sacred-texts.com
There is a being which is best, and greatest, and highest of all existing beings.
IF any man, either from ignorance or unbelief, has no knowledge of the existence of one Nature which is highest of all existing beings, which is also sufficient p. 37 to itself in its eternal blessedness, and which confers upon and effects in all other beings, through its omnipotent goodness, the very fact of their existence, and the fact that in any way their existence is good; and if he has no knowledge of many other things, which we necessarily believe regarding God and his creatures, he still believes that he can at least convince himself of these truths in great part, even if his mental powers are very ordinary, by the force of reason alone.
And, although he could do this in many ways, I shall adopt one which I consider easiest for such a man. For, since all desire to enjoy only those things which they suppose to be good, it is natural that this man should, at some time, turn his mind’s eye to the examination of that cause by which these things are good, which he does not desire, except as he judges them to be good. So that, as reason leads the way and follows up these considerations, he advances rationally to those truths of which, without reason, he has no knowledge. And if, in this discussion, I use any argument which no greater authority adduces, I wish it to be received in this way: although, on the grounds that I shall see fit to adopt, the conclusion is reached as if necessarily, yet it is not, for this reason, said to be absolutely necessary, but merely that it can appear so for the time being.
It is easy, then, for one to say to himself: Since there are goods so innumerable, whose great diversity we experience by the bodily senses, and discern by our mental faculties, must we not believe that there is some one thing, through which all goods whatever are good? Or are they good one through one thing and another through another? To be sure, it is most p. 38 certain and clear, for all who are willing to see, that whatsoever things are said to possess any attribute in such a way that in mutual comparison they may be said to possess it in greater, or less, or equal degree, are said to possess it by virtue of some fact, which is not understood to be one thing in one case and another in another, but to be the same in different cases, whether it is regarded as existing in these cases in equal or unequal degree. For, whatsoever things are said to be just, when compared one with another, whether equally, or more, or less, cannot be understood as just, except through the quality of justness, which is not one thing in one instance, and another in another.
Since it is certain, then, that all goods, if mutually compared, would prove either equally or unequally good, necessarily they are all good by virtue of something which is conceived of as the same in different goods, although sometimes they seem to be called good, the one by virtue of one thing, the other by virtue of another. For, apparently it is by virtue of one quality, that a horse is called good, because he is strong, and by virtue of another, that he is called good, because he is swift. For, though he seems to be called good by virtue of his strength, and good by virtue of his swiftness, yet swiftness and strength do not appear to be the same thing.
But if a horse, because he is strong and swift, is therefore good, how is it that a strong, swift robber is bad? Rather, then, just as a strong, swift robber is bad, because he is harmful, so a strong, swift horse is good, because he is useful. And, indeed, nothing is ordinarily regarded as good, except either for some utility ‑‑ as, for instance, safety is called good, and p. 39 those things which promote safety ‑‑or for some honorable character ‑‑ as, for instance, beauty is reckoned to be good, and what promotes beauty.
But, since the reasoning which we have observed is in no wise refutable, necessarily, again, all things, whether useful or honorable, if they are truly good, are good through that same being through which all goods exist, whatever that being is. But who can doubt this very being, through which all goods exist, to be a great good? This must be, then, a good through itself, since ever other good is through it.
It follows, therefore, that all other goods are good through another being than that which they themselves are, and this being alone is good through itself. Hence, this alone is supremely good, which is alone good through itself. For it is supreme, in that it so surpasses other beings, that it is neither equalled nor excelled. But that which is supremely good is also supremely great. There is, therefore, some one being which is supremely good, and supremely great, that is, the highest of all existing beings.