The French philosopher René Descartes is best-known for his statement Cogito, ergo sum – I think, therefore I am. But what is the deeper philosophy behind this statement?
When trying to understand Descartes’ philosophy, it is important to bear in mind that he was not only a philosopher, but also a mathematician – any high school student has to contend with Cartesian coordinates, probably the best-known result of his work in mathematics. Descartes wanted to introduce mathematical rigour into philosophy, and this meant that he first had to get rid of everything that was without rigorous foundation. He radically questioned everything: our perceptions, and reality as it appears to us – it could all be just a dream. Maybe none of it really exists? Some truths, however, pass the test of this radical doubt: basic notions of time, space, and also mathematical truths like 2+2=4 remain true, even in dreams.
This is the point where Descartes realizes that one thing is undoubtedly true: our mind, our awareness exists. Whatever is going on in this awareness may be deeply deluded, but we can be sure that we exist, because we have an immediate experience of our awareness. This is an undebatable truth. Unfortunately, Descartes let himself slip into arguments that are not quite as rigorous as his initial idea: he tried to prove the existence of God, starting from his initial argument. He probably felt the need to do this because, even though his initial argument is very strong, it is useless if we are interested in making statements about anything except our own existence. Descartes’ argument is the following: we find in ourselves the idea of a perfect being (God). Since we are imperfect and limited, it is impossible that we generated this idea by ourselves, which necessitates the existence of God, who must have planted the seed of this idea into us. If we assume, however, that anything that we think can be wrong and is not provable with mathematical rigor, it is obvious that this argument of the existence of God is somewhat contrived and much weaker than his initial argument.
Descartes began a tradition in Western philosophy: the need to find a point of absolute truth, which would allow the philosopher to attach a philosophical framework to it. Schopenhauer, for example, sought this point of absolute truth in “will”. Ultimately, all of these attempts are doomed: the points of absolute truth philosophers have come up with are often questionable (Schopenhauer’s “will”, for example, strikes me as a rather arbitrary choice, lacking in substance). Even when they are convincing, as in the case of Descartes, they are of little use. The instant we leave the point of absolute truth, the mathematical rigour is gone – we have to use our flawed minds to come up with arguments, which means that they lack the strength and clarity of the basic assumption.
So why read and think about Descartes, if his thinking was a useless exercise in applying mathematical rigour to philosophy, without practical use? First of all, his radical doubt reminds us to be humble, it reminds us of the fact that we know very little, and that the things we know are doubtful. This is a recurring theme (Socrates had the same realization) and probably the most fundamental teaching of philosophy – we know nothing. Most of us are quick to nod here, but we quickly forget this truth and walk around in our everyday lives, armed with notions and opinions and judgments, convinced that we are right: if our preferred politician were in power, the economy would be better. Our coworker is a bad person. Our friend took a wrong decision. People in general are unreliable. Do we really know these things? If we were to investigate with Descartes’ rigour, we would have to admit that most are guesses at best, and that we should be much more humble in our assessments.
Ideologues in particular present a worldview that is based on fixed assumptions that are presented as undoubtedly true. The worldview rests on these assumptions, and everything else is viewed from the angle of these assumptions. The basic assumption of Nazism was that there is a struggle of the races for world domination. Communism taught that class struggle would inevitably lead to the victory of the working class and the emergence of Communism/Socialism. Religious ideologies are based on the assumption that one religion is “true” and superior and that everyone else should be converted or killed. Trumpism teaches that there is a conspiracy of the liberal elite and foreign powers, that this conspiracy wants to destroy the United States, and that Donald Trump is the savior who will prevent this from happening.
Descartes’ skepticism teaches us to closely examine the basic assumptions of our worldview, and the conclusions we draw from them. Are they really as solid as they look to us, or are we fooling ourselves?