Today’s question: If knowledge requires certainty, is there anything at all we can know — and what, exactly, does the cogito secure?
I think it’s interesting how the entire first meditation can be read almost as priming the stage for the second. It makes me wonder, sometimes, about the actual order of writing — did the idea of the cogito happen before the Meditations were written, and then he guided the text towards that landing? Maybe we’ll never know. But it’s pretty clear that Meditation I is about clearing the board: about casting aside everything that can influence our decisions as far as Meditation II is concerned.
And I think he does this pretty well. He provides examples of why our senses can sometimes betray us, or why dreams cannot be considered truth — which is obvious. Although I think he does bring up a good point: everything in our dreams is based on something, in the same way that everything in art is based on something. Even with completely fictional concepts, they are either composed of things that are real, or the actual materials and items we use to fabricate these fictional entities are themselves real. So Descartes does give the concept of reality at least a fair shake.
And it is worth noting that the dream-and-art analogy is really Descartes’ own move — the painter argument in Meditation I — not something I am reading into him. I think it is also the reason the doubt has to keep escalating. If even our wildest dreams are recombinations of things that are real, then attacks on the senses and on dreams leave certain truths untouched: a square still has four sides; two and three still make five. It is only with the all-deceiving demon — a power that can corrupt even the simplest mathematics — that the board can really be cleared.
He goes through a number of processes to clear the slate and make himself ready for his atomic point — his Archimedean point — which is the famous start to frame our quest: let’s start from base principles. Plato was approaching it from the other side, breaking down what we know into its atomic components; Descartes is saying, let’s start from the other end with what we absolutely know, and see how far we can go from there.
So what do we actually know right now? How does this come back to our quest for knowledge? Plato has told us that we cannot know things purely by breaking them down into their composing elements, but that this is a useful way to start to define them. He also tells us we cannot know things purely in terms of what they are not, but that this, too, is a good way to go about building a definition. Both aspects have their benefits. Descartes, on the other hand, is telling us something different.
Descartes is telling us that we have at least one principle we can stick to: that we exist because we are knowing, and to be knowing we must be here. We have at least one indivisible concept we can build from — we have arrived at his Archimedean point.
And I think what’s interesting about how Descartes gets us there is that it isn’t really a deductive move, the way “I think, therefore I am” might appear when written out. There is no premise plus premise leading to a conclusion. It is something closer to a performance — every time Descartes tries to doubt that he exists, the very act of doubting establishes the existence the doubt was supposed to dissolve. The point doesn’t arrive by reasoning to it; it arrives by trying to refuse it and discovering that you cannot.
From there, the question is no longer what is knowledge, but rather what can we know, based on what we already know?
Ultimately, I think this means that for our quest for knowledge, knowledge must exist. Knowledge must exist because we exist; if we can conceive of something, a concept exists; if we can know something, then knowledge must exist. We can know something — namely, that we exist — and therefore knowledge itself must exist.
So, looking back at Meditation I, was everything he was saying here actually necessary to get to that point? I think that depends on his reader, and on whether they grant the assumption that nothing exists. If he has to build up to that in order not to be rejected, then maybe it makes sense that all of these examples — of why our senses cannot be trusted, and why our daily concepts and perceptions need to be questioned — are important.
This is again, like yesterday, perhaps a difference in our contemporary context. For example, when we look at the dream section of Descartes’ first meditation, we in the modern day are well aware of techniques to tell whether or not we’re dreaming. These are well known, or at least in my experience — I’m not going to get into that here. But the concept of some sort of malicious actor preventing us from being able to understand the truth is perhaps more meaningful today, because of the ongoing massive increase in things like fake news. A lot of what we might assume to be truth we can, at least in this day and age, more confidently say could be false; and therefore we need to be able to validate things more often, more concretely, and more thoroughly than one might hope.
So I think it would be disingenuous to say that Descartes is speaking only to his own time, and that his examples are no longer necessary. Even with more modern ideas of the self — are we just in a hologram? are we in a computer simulation? — the ultimate truth of I think, therefore I am still holds. And especially when we start dealing with examples of artificial intelligence: when experts are constantly crowing about the imminent arrival of AGI, and chatbots that can already beat a Turing test but which we can categorically know are not sentient, then I think, therefore I am — and being able to prove sentience — becomes even more important.
And this is where the cogito starts to show its limits. It gives certainty only about the thinking happening right now, in the first person. From the outside, looking at any other agent — a chatbot, another human, a hypothetical AGI — the certainty does not transfer. I can know with absolute confidence that I am thinking; I can never have that confidence about anything else. The wall the cogito builds for us is also a wall it cannot reach across, and proving sentience in something other than ourselves is a separate problem the cogito alone will never solve.