I think, therefore I am

Surely you have already come across this famous phrase: I think, therefore I am. Do you know what it means? Many people believe that this phrase is an encouragement to critical thinking, to free speech or something of the sort, but in fact, this phrase has little to do with that.

This phrase is situated in a more philosophical context than you might imagine. But first let’s find out who its author is.

“I think, therefore I am”, who said?

The author of this phrase is René Descartes (1596-1650), physicist, mathematician, and considered to be the first modern philosopher.

His great contributions to science, mathematics, and philosophy made him an important figure in the Scientific Revolution of the 17th century.

One of his creations is analytic geometry, also called Cartesian geometry.

And what does “I think, therefore I am” mean?

With this sentence Descartes wanted to establish an indubitable truth; a truth so evident that no one could deny it without contradicting it. Bold, isn’t it?

His goal in establishing this absolute truth was to build a rigorous philosophical system.

Descartes was dissatisfied with all that philosophy that the medieval period had built. Medieval philosophy was anchored in Aristotelian philosophy and Christian thought (St. Augustine, Thomas Aquinas, etc.), and at the time of Descartes, they were already losing strength thanks to the new scientific discoveries.

For him, philosophy was still contaminated with supposedly true theses; theses that could not be sustained with a dose of doubt. In fact, this is what Descartes did, he placed all the supposed philosophical truths in the realm of doubt to try to find an absolute truth, impossible to refute.

What “truth” would hold up when put into the most radical doubt?

The senses deceive us

You could say that the world is real. You can’t doubt that my house, for example, doesn’t exist in reality. Well, Descartes has good arguments to prove the contrary.

According to the French thinker, we should not trust our senses too much. Who has never been deceived by his or her senses? Sometimes, we believe we see something and when we get closer, it is not what we imagined it to be.

From this, Descartes concludes that if the senses have fooled us once, they can fool us always. They cannot be trusted. Thus, he dismantles every kind of truth that derives from the senses.

The Evil Genius

You could also say that the mathematical calculations are true in any case: 1+1 equals 2 now and forever. Is it? Descartes doubts it.

For him, mathematics cannot be the most absolute truth he seeks, because there could be a kind of evil genius, a deceiving god, who makes us think that these things are true and self-evident, when in fact they are not.

Dream and reality

To conclude, Descartes further argues that we cannot be sure that our reality is not just a dream. Could it be that at this moment you are only dreaming? How would you prove otherwise?

Cogito ergo sum: the foundation of Cartesian philosophy

After destroying all human certainties, Descartes states that there is one truth that is in fact unquestionable: I think, therefore I am (cogito ergo sum, in Latin).

From the very fact of doubting, I know that I think and that I exist. If there were no thought and existence, there would be no possibility of doubting. This would be the most evident truth that man can conceive.

The foundation of all Cartesian philosophy is defined in this truth. What he then does is to try to depart from it and find new ones.

So this is not just a “cute phrase”. It has a strictly philosophical purpose.

Descartes, like every good philosopher, seeks the “truest truth” that thought can conceive. No other philosopher before him built a philosophical system based on this truth, so Descartes revolutionized the philosophy of his time.

Is it possible to disagree with “I think, therefore I exist”?

No sanity-minded person will deny this truth, but it is possible to deny the “I think, therefore I am” as the philosophical starting point, or as the only evident truth.

There were philosophers who disagreed with Descartes, because according to them the existence of the external world is self-evident, and that to deny it, as Descartes did, would be absurd.

The originality of human experience is always that of a being-in-the-world. We are not an absolutely thinking thing, we are beings incarnated in a body. In fact, thought itself only develops through contact with the external world. Therefore, to say that we are only a thinking thing is to destroy our experience of being essentially related to the world, to the not-self.

Our thinking presupposes our existence, but it also presupposes the existence of the world and of the other.

Finally, this shows us that in philosophy there is no unanimity. There is always room for dialogue.