Abstract
" Pactasunt servanda ", " agreements must be respected ". This formula, which still applies today, sums up the content of a clause in the edict that every magistrate in charge of a jurisdiction (praetor or governor) had to ensure was respected. This principle, as Ulpian comments(D., 2, 14, 1 pr.), derives from human nature(fides humana), but is in fact a cultural construct.
It's an example of how the Ancients constructed their past to explain the present. The image of Justice abandoning the land to injustice, in a regressive dynamic, explains the establishment of norms. It stands alongside another image, that of an ameliorative dynamic, in which man passes from the savage stage to that of a being living in a community, equipped with everything he needs to overcome his original vulnerability. This idea goes back to the materialist philosopher Democritus of Abdera, at the turn of the5th and 4th centuries, who inspired Epicurus(Capital Maxims, 31 ; 33), then Lucretius(De rerum natura, 5, 953-1149). A satire by Horace(Sermones, 1, 3) is in line with this thinking. Criticizing the Stoics' concept of justice, for which all faults deserve the same punishment, Horace develops the notion of " common utility, as it were the matrix of the just and the good ". Society can only be built through respect for the agreement not to harm one another, because of the need for mutual protection (which also applies to relations between friends). The premise is the creation of family ties (and relationships between men and women built not solely on sexual desire, but also on a solidarity - institutionalized in marriage - of which the upbringing of children is the strong point). This agreement would lead - according to Horace - to the birth of civic communities. For Epicurus and his Latin epigones, law is not innate, but the fruit of a construction that serves to guarantee mutual security.
The young Cicero, in the prologue to his rhetorical textbook De inventione, in contrast to the Epicurean vision, expounds the Stoic-Peripatetic motif of the man who is sociable by nature, living in community not so much to be safe as to satisfy his need to communicate with his fellow men (Aristotle, Pol., 3, 1278b, 17-23). The use of speech, by enabling the establishment of legal norms, becomes a catalyst for the city (even if backtracking is still possible, and eloquence can also be a factor of disintegration).
