René Descartes is considered by many to be the “father of modern philosophy,” having practiced skepticism to ascertain objective truths about the universe. In his time, Descartes produced a profound body of work that continues to impact the way we think about human existence.
But for all the theories Descartes proposed, one simple idea stands out as the most influential. In his native French, it’s written as “Je pense, donc je suis.” Translated into Latin, it reads, “Cogito, ergo sum.” But perhaps most familiarly, it’s written in English as “I think, therefore I am.”
Descartes was born in the Kingdom of France in 1596, and at a young age he enrolled in a Jesuit College in the town of La Flèche, where he was first introduced to the concepts of math and physics. Descartes went on to earn a law license — per his father’s wishes — and eventually moved to Paris in 1622. But it wasn’t until 1637 that Descartes published what’s considered now to be among the most influential philosophical works ever written: Discourse on the Method of Rightly Conducting One’s Reason, and Seeking Truth in the Sciences (say that 10 times fast).
Discourse on the Method, as it’s more commonly referred to, contains the first usage of Descartes’ now-iconic phrase, with the words “je pense, donc je suis,” appearing in part four of the treatise. A variant of this belief appeared in his 1641 treatise Meditations on First Philosophy, and it was first written in the Latin “ego cogito, ergo sum,” in 1644’s Principles of Philosophy. But throughout the many different contexts and translations, the general idea remains constant.
Essentially, the concept of “I think, therefore I am,” is rooted in extreme skepticism. Descartes based his entire philosophy around the idea of questioning everything, right down to one’s very existence. This stood in stark contrast to the beliefs of many earlier philosophers, who took things more at face value.
Some of those philosophers may have said something along the lines of, “I know the Earth exists because I can feel it under my feet.” But Descartes pushed back against this perceived reality and offered up the notion that everything we assume to physically exist may actually be a dream.
It was here that Descartes encountered an issue with embracing such unequivocal skepticism. It seemed impossible to deduce any objective truths or rational conclusions about the universe once he’d begun to believe humans may not actually exist to begin with.
But Descartes made sense of it all by 1647, the year in which he wrote The Search for Truth by Natural Light, which was posthumously published in 1684. This was the only time he phrased his idea as “dubito, ergo sum,” which translates to, “I doubt, therefore I am.”
To Descartes, the fact that we as humans are capable of doubt or thought is enough to demonstrate any individual’s existence. He argued that human existence isn’t based on anyone’s surroundings, which can change and be perceived differently depending on the person in question. Instead, the only thing we can know for certain is that we possess the ability to think, and that alone serves as proof that we all exist.
Some philosophers have pushed back on this famous axiom, including 19th-century thinker Søren Kierkegaard. He took umbrage with the fact that the phrase assumes the existence of an “I,” which in turn invalidates the logic of Descartes’ premise.
German philosopher Friedrich Nietzsche offered an additional critique, stating that “cogito, ergo sum” establishes the activity of thinking more than it does any sort of individual existence. It’s up to each of us to determine whether these critiques resonate more than Descartes’ initial proposal, or vice versa.
Descartes’ life came to an end in 1650, though his legacy continues to live on in the form of a belief system known as Cartesianism, which views the body and the mind as two distinct entities. To those who believe in this concept of mind-body dualism, the body’s sensory experiences can mislead us to believe skewed “realities” about the world. On the other hand, this belief posits that internal thought and doubt are the only things we can trust for certain, even if they fail to provide us with all the answers we seek.
Featured image credit: Stefano Bianchetti/ Corbis Historical via Getty Images
