Kant’s earlier work had sensitized him to the dynamics of nature, and this would have made it all the easier to marvel over celestial mechanics while stargazing. Thinkers with a dynamic bent, from Pythagoras to Kepler, listened to the music of the spheres. As Kepler’s Harmonice Mundi (1619) shows, the music of the spheres is not a poetic delusion but a heuristic device.[17] It turns one’s attention on cosmic patterns, the harmonies and beats that point to laws. As the Spin-Cycle essay illustrates, Kant followed in the footsteps of such thinkers.  Listening to the music of the spheres would generate the astonishing discoveries of the 1750s.