Selection from City of God
Source: City of God Against the Pagans Book 11, Chapter 26. W.M Green, translator. Loeb Classical Library. Cambridge, M.A.: Harvard University Press.
26. On the image of the most high Trinity that in a certain fashion is found in human nature even before a man has attained bliss.
We too as a matter of fact recognize in ourselves an image of God, that is of this most high Trinity, even if the image is not equal to Him in worth, but rather very far short of being so. The image is not co-eternal and, to sum the matter up briefly, it is not formed of the same substance as God. Yet it is nearer to him in the scale of nature than any other thing created by him, although it still requires to be reshaped and perfected in order to be nearest to him in its likeness to him also. For we both are and know that we are, and we love our existence and our knowledge of it. Moreover, in these three statements that I have made we are not confused by any mistake masquerading as truth. For we do not get in touch with these realities, as we do with external objects, by means of any bodily sense. We know colours, for instance, by seeing them, sounds by hearing them, odours by smelling them, the taste of things by tasting them, and hard and soft objects by feeling them. We also have images that closely resemble these physical objects, but they are not material. They live in our minds, where we use them in thinking, preserve them in our memory, and are stimulated by them to desire the objects themselves. But it is without any deceptive play of my imagination, with its real and unreal visions, that I am quite certain that I am, that I know that I am, and that I love this being and this knowing.
Where these truths are concerned I need not quail before the Academicians when they say: “What if you should be mistaken?” Well, if I am mistaken, I exist. For a man who does not exist can surely not be mistaken either, and if I am mistaken, therefore I exist. So, since I am if I am mistaken, how can I be mistaken in believing that I am when it is certain that if I am mistaken I am. Therefore, from the fact that, if I were indeed mistaken, I should have to exist to be mistaken, it follows that I am undoubtedly not mistaken in knowing that I am. It follows also that in saying that I know that I know, I am not mistaken. For just as I know that I am, so it holds that I know that I know. And when I love these two things, I add this same love as a third particular of no smaller value to these things that I know. Nor is my statement, that I love, a mistake, since I am not mistaken in the things that I love; yet even if they were illusions, it would still be true that I love illusions. For on what grounds could I rightly be blamed or prevented from loving illusions, if it were a mistaken belief that I love them? But since these things are themselves true and certain who can doubt that, when they are loved, the love itself is also true and certain? Furthermore, it is as true that there is no person who does not wish to be as that there is no person who does not wish to be happy. For how can a person be happy if he is nothing?