This Chapter brings together two lines of investigation about the natural philosophical structure and aims of Le Monde. First, it shows that Descartes' often belittled vortex celestial mechanics was a serious intellectual construct: It was Descartes' technical answer to the natural philosophical challenge posed by realist Copernicanism, and hence it was also a serious gambit in the natural philosophical contest. The centrality of the vortex mechanics to all the other topics addressed in Le Mondeis demonstrated. Second, this Chapter explores the celestial mechanics as a conceptually hybrid entity. On the one hand, it is shown that the vortex celestial mechanics has a genealogy reaching back through the physico-mathematics studied in earlier chapters. But, on the other hand, we also learn that the vortex mechanics was a piece of generic natural philosophical discourse, understandable as such by any member of the educated culture of natural philosophizing. This shows that Le Mondewas simultaneously the climax of Descartes' trajectory in physico-mathematics and the first iteration of a systematic natural philosophizing, emergent from that carapace.