Is there anything we can be certain of? Aren’t the two patriarchs in the history of philosophy, Descartes and Socrates, always going on about what we don’t know? Descartes, in his experiment of fundamental doubt, stripped away everything that could err in principle. Socrates spent a career suggesting to everyone he encountered that they didn’t know as much as they thought. Skepticism, a la Descartes or Socrates, can be misconstrued as suggesting that we cannot really know anything. But ultimately this fails like any fully skeptical position, in that it undermines itself. Descartes was searching for certainty, and said he found it in the act of thinking. Socrates thought certainty rest upon the law of non-contradiction. Were they right in seeking an epistemological bedrock?
The short answer is yes: there must be something that which we know by mere apprehension, or when we comprehend the terms. There must be some kind of self-evident truth in order to get the reasoning process started, as reason cannot justify reason itself. Both Descartes and Socrates employ skepticism as a tool; as a means but not an end. So how did they conceive of this bedrock of knowledge?
Descartes cogito ergo sum is more or less known by everyone: “I think, therefore I am”. The only thing, he says, that cannot be doubted is that I am thinking. For even to doubt that you are thinking is to think. He withdraws from the world of real objects in effort to find sure footing for knowledge. However, it turns out he took the world with him. He cut the bridge from our mind to real things. If our thinking is the only thing we can be sure about, then the world is subjugated to our thinking. He places a metaphysical primacy on the mind over the world; and if so, why not also a causal primacy? Perhaps the real world doesn’t exist at all? Perhaps we simply dream it into being?
How does Socrates differ? The basic platform from which he departs is from the law of non-contradiction. This law states something either exists in a particular way or sense, or it doesn’t. The world cannot be both spinning on its axis and not spinning on its axis in the same way at the same time. These contradictory ideas cannot both be true. This is not simply a feature of thought, but a feature of reality itself which governs our thinking. Even the most basic thought employs this law. Take Descartes’ statement “I think therefore I exist”: this cannot mean both I think and I don’t think, or I exist and I don’t exist. It excludes the contradictory.
Also, it’s apparent that the nature of thought includes intentionality. Our thinking is about something: it has content of which is not “thought” itself. When we think, we think about the bad pop music playing at Einstein’s, or about the events of the day, or about the “elephant in the room”. If we wish to say we are certain of the fact we are thinking, this becomes a meaningless statement if we sever “thinking” from things. If we are merely thinking, we are merely thinking about something. If there is nothing about which to think of, then we cannot think at all. A mirror cannot reflect itself.
In sum, we notice that both of their epistemological bedrocks involve thought, and a thinking subject. Descartes’ is reduced to simply that, while Socrates has the subject participating in the larger and irreducible reality. Descartes’ cogito ergo sum is basically true, but the term “think” becomes ambiguous and confused when it is used in a way to not consistent with the nature of thinking. Descartes has half of the answer, but by not considering the necessary implications of thought itself he removes it from the context to comprehend it.