Descartes, Eat Your Heart Out, or: Augustine's Thoughts By a Fireplace

Don't worry. This isn't going to be another rant against everybody's favorite philosophical whipping boy, poor old Rene Descartes. I came across the following quote a while back in The City of God by the eminent Aurelius Augustinus, otherwise known as St. Augustine. In the 26th Chapter of Book II, he says the following:

"I am not at all afraid of the arguments of the academicians: What if you are deceived? For if I am deceived, I am. For he who is not cannot be deceived. And if I am deceived, by this same token I am. And since I am, if I am deceived, how am I deceived in believing that I am. For it's certain that I am, if I am deceived. Since therefore I the person deceived, should be even if I were deceived, certainly I am not deceived in this knowledge that I am. And consequently, neither am I deceived in knowing that I know. For as I know that I am so I know this also, that I know."

Now it's been a little while since my formal philosophy-studying days or since I've read any Descartes, but doesn't this sound uncannily familiar? Wasn't Descartes' claim to fame, or infamy, depending on your perspective, supposed to be his innovation in proving his own existence, his cogito ergo sum? I for one feel cheated. Not only does Augustine seem to accomplish the same thing as Descartes did, he did it over a millennium earlier and quite elegantly to boot. It's interesting though, to see how the two thinkers come to the seemingly same argument and what they intend to do with it. For Descartes, his cogito is his attempt to ground an unshakably sound philosophical system, the baseline from which he intended, and attempted, to go on to prove everything else that interested him, like the existence of God for example. For Augustine, the argument that, at the very least, he has no reason to doubt that he exists, comes across more like his way of making quick work of what seems to him like a rather silly line of questioning. One pictures the ever august Bishop swatting away, like so many bothersome flies, the arguments of a rabble of pestering academics who have so much time on their hands they've forgotten who, or even that, they are.