The objective of the research project is to investigate the preceptive dimension of the word in Roman legal history, through a mapping and an in-depth examination of the countless issues that gravitate around this thematic nucleus. If the archaic experience fully reveals its distance from us (but already from the late republican developments) precisely because of a peculiar use of the word – not infrequently at the centre of phrases with an undoubtedly performative character, related to a dimension in which there was not even a caesura between the juridical, ethical and magical-sacral sphere –, for this reason not mostly (or only) the persistence of such connotation of language in the later seasons deserves attention. The word has maintained its absolute centrality from many points of view, although now under another guise: “secular” and “rational”, more flexible and open with respect to the intentions of the legislator or the autonomy of the parties (but no less rigorous and binding). A wide-ranging, inclusive and coordinated as possible analysis on such issues would already constitute an appreciable and largely new result.