My point of departure is provided by a short but highly important chapter, "A la recherche de l'Empyree, by the late Etienne Gilson in his last series of studies on Dante published in 1974 under the general title Dante et Beatrice. In it he makes the point which few of us had noticed before that although commentators frequently employ the term "cielo empireo", Dante himself uses it only once in the Commedia, and then at a very early stage of the Inferno, where he speaks about Aeneas as being chosen as father of Rome and its empire: "nell'empireo ciel per padre eletto" Inf. II, 21). In the Paradiso, where one would expect him to make rather lavish use of the expression, particularly in the concluding cantos, he avoids it altogether. Why, we may ask?

Gilson, following on Nardi, answers that Dante had by now caught up with the later thirteenth century theologians, including St Thomas Aquinas, who were trying to disengage the notion of Paradise, or heaven proper, from the Ptolemaic scheme of physical heavens. Dante, too, it seems, was by now uncomfortable with the idea of a tenth unmoving heaven enclosing the nine revolving spheres and sharing, at least by analogy, in their materiality, in however tenuous and refined a sense this be understood. After all, he had written years before in the Convivio that the "cielo empireo" was "il sovrano edificio del mondo", and lest we think that this was merely metaphor, he had used an argument which, as Nardi points out, was still taught in the Arts Faculties when the theologians were fighting shy of it.