Cogito ergo sum?

One of the most famous phrases in Latin comes from the writings of Descartes, the French philosopher who ushered enlightenment and modern philosophy in the early 17th century. I think therefore I am, he wrote in his famous manuscript called Meditations. Many thinkers since then disagreed. They claim that Descartes is making a mistake, equating his being with thinking, or they say it is more correct to say: I feel therefore I am, etc. Yet, that's a poor reading, or a superficial understanding of Descartes who was a brilliant mathematician as well as a giant among philosophers. Please don't let all that discourage you from trying to get to the bottom of what Descartes was talking about. Let's get to it here. I promise you it won't be long and it won't be obscure. 

Let's start where he started: when I am dreaming at night, I don't know that I am dreaming - except for the rare lucid dreams, but, I find that out as soon as I wake up! So, we can ask, just like Descartes did, how do we know that what we call our life is not a dream? Ask yourselves. Usually, the answer is that we don't know (Remember Socrates?). After all, there is the impending death of the human body, and not many seem to come back from the afterlife and testify that, yes, this limited human experience is just a dream. Descartes was a very good mathematician, in fact one of the greats, for he came up with the Cartesian system which connected geometry and algebra and gave us the famous equations with two unknowns, x & y, for straight lines (y = mx + c), parabolas (y = ax * x + bx + c) and circles (x*x + y*y = r*r) and so on. So, Descartes admitted to himself, just like Socrates, that he didn't know that all of this wasn't a dream. But, he wanted to find out. As we do in math (see our basic math proof), he wanted to start on solid ground and go from there. Otherwise, he feared, that we could be lost in confusion, a tangle of contradictions, a kind of hell we don't want to get stuck in. Afterall, we do live in an uncertain world. Would it not help to have some solid ground? Some resort to religion, but Descartes wanted to go beyond all belief. He had faith in reason. 

So, in life, what is our solid ground? Please ask yourselves and meditate on it a bit before reading further. In fact, is there a solid ground? This conundrum was not much of a problem for Descartes because he was adept in the use of proof techniques, the deductive, logical proofs as well as the proof by contradiction that we talked about earlier. But, still, a breakthrough was needed. Do you remember our proof for largest number or proof for largest prime? Well, just assume something, assume one thing to be true and see where it takes you.

That's what Descartes did. Instead of believing anything suspicious about life, or even about himself, he started with a very simple, seemingly naive assumption: I don't exist. Or, I am not. No being here now. Do you have a solid proof that you exist? That's what D wanted, too. But, once we accept that we don't know, and we are at peace with it, we can get some inkling, some inspiration. And that's what happened to D, too. He realized a basic fact of subjective experience: I am aware of my thoughts. Remember that the statement "I don't exist" is a manifestation of a thought, isn't it? Please check for yourself. Yet, I know that I am aware of my thoughts. So, there is this mysterious "I" who is aware of the statement: "I don't exist." And, therein Descartes discovered the contradiction! If there is a contradiction, then, there is something wrong. What could that be other than the only assumption we made: "I don't exist." So, it must be false. Meaning, it is false that I don't exist. Therefore, I do exist. I am real. Well, duh, everybody knows that, don't they? Actually, it appears that many are confused. Check this out where the novelist John Green talks about the teenage protagonist in his latest novel asking her mom: "Mom, am I real?" Had she read this, she wouldn't have asked that question, would she? Why wonder when we have solid proof beyond any reasonable doubt?  We could be wondering instead who or what we are, or what we are not.

And, that proof is what made Descartes famous! Can you believe it? Isn't it obvious? Well, hindsight is 20/20 as they say. But, Descartes is saying more than something so obvious. He is also saying that you and I can agree objectively on some fundamental facts about life. Each of us can do this exercise and prove it to ourselves that we exist. Yet, I don't really know that you or anybody else are aware of any thoughts. I am only aware of my own thoughts. I am aware that you might be saying the same things, or very different and even surprising things, but speech is not thought. Speech is wonderful, too and human language is another mystery (and another page hopefully), but it is only a manifestation of thought. Free speech doesn't mean free thought. We don't really know what thoughts are. We are only aware of them in our own heads. This is known as solipsism in philosophy of mind and metaphysics. 

Let's recap: we proved, along with Descartes, that we know that we exist. We have solid proof. Descartes didn't mean that we exist because we think. No, he simply meant that we know that we exist because we are aware of thoughts. 

So, what do you think? Is he on to something, or was he wrong? After all, Socrates insisted that he knew not :-). But, thanks to Descartes, we know at least one thing for sure. Wait, that makes two, now: 

1. I know that I don't know.

2. I know that I exist. 

Don't you love wisdom? Can you add a third? Not just "this I believe," but this I know, truly. Wouldn't it be great to hop on the shoulder of those two great explorers and see farther and know further? Godspeed!