Pierce Arnold - Fallible Memory With The Cogito 4/27/2026

Something that we talked about in class this semester was the idea that memory is no less true than fiction. To summarize, this is because our memories are known to be inaccurate, and they are just an imaginary image of a world that doesn’t exist (or at least no longer exists). Thus, it is similar to fiction because we can use the lessons learned from it to help us in the present, but we cannot assume it is an accurate representation of the world. This concept has an interesting implication on the Cogito, the famous statement made by Rene Descartes in acknowledgment of his own existence made in his meditations on philosophy. The Cogito proposes that in order for me to have a thought, there must be a thinker that caused that thought, after all without a thinker there would be no thoughts. Thus, just thinking the thought “I think” requires that you exist in order to think it, “Therefore I am”. That said, given this new idea we talked about in class about how memory is fallible and cannot be used as an absolute measure of anything, it would be faulty to say “I thought therefore I was”. Changing the Cogito to the past tense invalidates it because the whole point is that Descartes is trying to put together a fool proof idea that has no chance of being wrong. He writes in his meditation “Often in my dreams I am convinced … that I am sitting by the fire in my dressing-gown – when in fact I am lying undressed in bed”. Because of the fact that Descartes is trying to rebuild his worldview starting from a place of complete doubt, he must doubt his own mind, which as noted above, can convince him that something is happening or has happened that is simply not the case. When he (or anyone) is dreaming, his mind convinces him he is somewhere he is not, doing something he is not, with a past memory of things which did not actually happen. This happens to most people from time to time, perhaps you once had trouble remembering if a certain memory or piece of information was real or if you were simply remembering a dream. So if memories cannot be trusted just as the senses cannot, the Cogito only works in the present moment. One cannot infallibly prove that one has existed in the past, one can only deduce that one exists presently.