The Somnium Scipionis or Dream of Scipio occupies the final book of Cicero’s de Republica, and was familiar to medieval readers thanks to its incorporation into Macrobius’s extremely influential commentary. A product of the late-republic era of the Roman Empire, Cicero’s text offers a spatially inflected commentary on imperial conquest in which the ocean plays a critical role. In the dream, young Scipio Aemilianus finds himself perched high amongst the stars with the ghost of his grandfather, Scipio Africanus. Upon seeing his grandson focus his gaze upon his earthly home, Africanus schools him on the ordering of the cosmos and its nine harmonising spheres. That lesson on the grandeur and concord of the universe, however, does not prevent Scipio from singling earth out for his continued attention, a move that prompts the following commentary by Africanus:

Again I see you gazing at the region and abode of mortals. If it seems as small to you as it really is, why not fix your attention upon the heavens and contemn what is mortal? ... You see, Scipio, that the inhabited portions on earth are widely separated and narrow, and that vast wastes lie between these inhabited spots, as we might call them; the earth’s inhabitants are so cut off that there can be no communication among different groups. You see that the earth is girt and surrounded by certain zones. ... There are two that are habitable, and of these the southern zone, in which the inhabitants press their footprints opposite to yours, has no contact with your race; the other, northern, is inhabited by the Romans. But look closely, see how small is the portion allotted to you! The whole of the portion you inhabit is narrow at the top and broad at the sides and is in truth a small island encircled by that sea which you call the Atlantic, the Great Sea, or Ocean. But you can see how small it is despite its name!

As James Romm has pointed out, Africanus’s lesson on geography carries an ethical message regarding how a statesman should seek not earthly glory but heavenly wisdom. Himself a world conqueror, Africanus does not stress the territorial extent of the empire but rather its limits.