Cogito ergo sum

I think, therefore I exist

This is not a quote from an ancient author, but from a seventeenth century French philosopher. Of course, Rene Descartes (1596-1650). Although Descartes chose to write his seminal work, the Discourse on Method, in French (so that, in his words, "even women can understand it") and not in the international scientific language of the time, Latin, the quote that condenses its fundamental idea has become famous in that latter language and not in its original version: "Je pense, donc je suis." The Discours de la methode was first published in 1637 as an introduction to a number of other studies. A Latin version was finally published in 1656 under the title Dissertatio de Methodo
Cogito ergo sum is one of the most popular Latin quotations. Its meaning is not, however, equally well known. Descartes's assertion may seem, at first glance, trivial, but it must be understood in its context. In the sixteenth and seventeenth centuries, philosophical skepticism was in a boom phase. It was a time of bloody wars of religion in which opposing dogmas generated in intellectual circles a strong tendency to relativism. To this was added the influence of the popularity of some ancient skeptic philosophers such as Sextus Empiricus. Descartes's goal in his Discourse on Method was to fight this skepticism and to provide a basis on which human knowledge could be developed. In the search of that unquestionably principle, Descartes applies systematic doubt to reject any assertion with the slightest possibility of falsehood. In this way he discovers that one can doubt about almost anything: the information our senses give us is not reliable, we easily fall prey to illusions, and there is no guarantee that the everyday world we experience is not just a fantasy of our own conscience or -as suggested by Descartes himself- the deception of a malignant deity.
Doubt seems, therefore, to destroy everything and leave no solid foundation for knowledge, but Descartes finds a point at which doubt must necessarily stop: there is a person who is thinking that everything is false and, if this person is thinking, this means she exists and that cannot be doubted. That is the idea expressed in the quotation under discussion, Cogito ergo sum. In his search for a method based on a totally rational foundation, Descartes finds a fundamental and undeniable truth: the existence of the self as the basis of all acts of unquestionable knowledge.
After finding this preliminary truth, Descartes extracts from it a general criterion that allows him to identify other truths: every simple intuition must be true or, put another way, all clear and distinct ideas must be true. I think that Descartes here contradicts the first and central of the four methodological principles he had laid down in the second part of his Discourse on Method: "not to accept as true anything, if there is not evidence that it is". Now, that an idea is clear and distinct is not enough evidence of veracity, besides, the clarity of an idea is appreciated differently by different people. As the humanist, historian and philosopher Giambattista Vico (1688-1744) said, if an idea seems us clear and distinct that does not mean it's true but only that we believe in it.


concedo nulli

I yield to nobody

The Romans worshiped in the figure of the god Terminus the sanctity of boundary stones. According to legend (Livy, 1.55), when king Tarquin began construction of the temple of Jupiter on the Capitol, he ordered the removal of the altars and shrines of all the gods that were worshiped there, so the area could be devoted exclusively to the king of the gods. All were transferred without problems, except for Terminus, represented with a stone that could not be removed. The Romans saw in this fact a manifestation of divine will, and let the rock inside the temple. Hence the expression "I yield to no one", because Terminus had refused to yield to Jupiter himself. This fact was interpreted as an omen, meaning that the dominion of Rome would be everlasting. The prophecy proved valid for centuries.
The celebrity of the sentence “concedo nulli” is due to Erasmus, who took it as a personal motto in 1509, adopting the old god Terminus as its emblem. The young Erasmus was then in Italy, and began to enjoy international recognition for his work and abilities. Apparently, Erasmus received from his pupil Alexander Stewart a gem depicting the god Terminus, and this is what inspired him to take the image of the god and the Latin quotation discussed here as personal emblems. They appear in a famous commemorative medal minted for Erasmus, whose image you see below. Erasmus is also shown next to the god Terminus in a famous engraving by Holbein.

Erasmus' enemies saw this motto as a sign of intolerable arrogance. In 1528 Erasmus wrote a letter justifying his choice of these words and trying to disarm his critics: the "epistola apologetica de Termini sui inscriptione concedo nulli" There, the great humanist stated that the term did not represent his own words, but those of death, the only one that yields to nobody. But this explanation did not satisfy his enemies. Written almost twenty years after the original stay of Erasmus in Italy, it seems, in fact, a later reworking. Humility was never one of Erasmus virtues. Posterity has been, however, more benign in judging Erasmus than his contemporaries.


Habent sua fata libelli

Books have their fates
Only a tiny fraction of the literary production of the ancient world has survived. This fraction has been transmitted by a very thin thread that throughout history was countless times close to breaking. Reflecting on the hazards that have determined what has survived and what has perished, it is inevitable not to agree with this statement: books, like men, have their fates.
The author of the quoted sentence is an example of this process. The grammarian Terentianus Maurus lived in the second century AD and was of African origin, as its name suggests. His major work, De litteris de syllabis, de metris (About pronunciation, syllables and metric), is conserved only in a fragmentary state. Forgotten during the Middle Ages, a manuscript with the text was discovered in 1493 and disappeared shortly after the first printed edition was published in Milan in 1497.
The most curious fate of some books is that their content is sometimes misunderstood or interpreted in a very different way from that desired by the author. Terentianus' phrase is a clear example, the meaning with which we have discussed it here and which is often cited, is not the one he intended. The verse from which it was taken reads:
Pro captu lectoris libelli habent sua fata
Books have their fates according to the reader's capacity