“One solution to the problem has been proposed by Maria Corti (1981: 46ff). It is, by now, generally accepted that we cannot regard Dante as simply an orthodox follower of the thought of St. Thomas Aquinas.
According to circumstances, Dante used a variety of philosophical and theological sources; it is furthermore well established that he was influenced by various strands of the so-called radical Aristotelianism whose major representative was Siger of Brabant.
Another important figure in radical Aristotelianism was Boethius of Dacia, who, like Siger, suffered the condemnation of the Bishop of Paris in 1277. Boethius was a member of a group of grammarians called Modistae, and the author of a treatise, De modis significandi, which–according to Corti–influenced Dante, because Bologna was the focal point from which, either through a stay in the city, or through Florentine or Bolognese friends, such influences reached Dante.
The Modist grammarians asserted the existence of linguistic universals–that is, of rules underlying the formation of any natural language. This may help clarify precisely what Dante meant by forma locutionis. In his De modis, Boethius of Dacia observed that it was possible to extract from all existing languages the rules of a universal grammar, distinct from either Greek or Latin grammar (Quaestio 6).
The “speculative grammar” of the Modistae asserted a relation of specular correspondence between language, thought and the nature of things. For them, it was a given that the modi intelligendi and, consequently, the modi significandi reflected the modi essendi of things themselves.
What God gave Adam, therefore, was neither just the faculty of language nor yet a natural language; what he gave was, in fact, a set of principles for a universal grammar. These principles acted as the formal cause of language: “the general structuring principle of language, as regards either the lexicon, or the morphological and syntactical components of the language that Adam would gradually forge by living and giving names.” (Corti 1981: 47).
Maria Corti’s thesis has been vehemently contested (cf., in particular, Pagani 1982; Maierù 1983). It has been objected that there is no clear proof that Dante even knew the work of Boethius of Dacia, that many of the analogies that Maria Corti tries to establish between Dante’s text and Boethius cannot be sustained, and that, finally, many of the linguistic notions that one finds in Dante were already circulating in the works of philosophers even before the thirteenth century.
Now, even if the first two objections are conceded, there still remains the third. That there were widespread discussions of the subject of universal grammar in medieval culture is something that no one, and certainly not Corti’s critics, wishes to place in doubt.
As Maierù puts it, it was not necessary to read Boethius to know that grammar has one and the same substance in all languages, even if there are variations on the surface, for this assertion is already found in Roger Bacon.
Yet this, if anything, constitutes proof that it was possible that Dante could have been thinking about universal grammar when he wrote DVE. If this is so, he could have conceived of the forma locutionis given by God as a sort of innate mechanism, in the same terms as Chomsky’s generative grammar, which, interestingly enough, was inspired by the rationalist ideas of Descartes and sixteenth-century grammarians who, in their turn, had rediscovered the ideas of the medieval Modistae.
Yet if this is all there is to it, what is the point of the story of Babel? It seems most likely that Dante believed that, at Babel, there had disappeared the perfect forma locutionis whose principles permitted the creation of languages capable of reflecting the true essence of things; languages, in other words, in which the modi essendi of things were identical with the modi significandi.
The Hebrew of Eden was the perfect and unrepeatable example of such a language. What was left after Babel? All that remained were shattered, imperfect formae locutionis, imperfect as the various vulgar Italian dialects whose defects and whose incapacity to express grand and profound thoughts Dante pitilessly analyzed.”
Umberto Eco, The Search for the Perfect Language, translated by James Fentress, Blackwell. Oxford, 1995, pp. 43-5.