In this paper I reconstruct Schlegel's idea that romantic poetry can re-enchant nature in a way that is uniquely compatible with modernity's epistemic and political values of criticism, self-criticism, and freedom. I trace several stages in Schlegel's early thinking concerning nature. First, he criticises modern culture for its analytic, reflective form of rationality which encourages a disenchanting view of nature. Second, he re-evaluates this modern form of rationality as making possible an ironic, romantic, poetry, which portrays natural phenomena as mysterious indications of an underlying reality that transcends knowledge. Yet Schlegel relies here on a contrast between human freedom and natural necessity that reinstates a disenchanting view of nature as fully intelligible and predictable. Third, therefore, he reconceives nature as inherently creative and poetic, rethinking human creativity as consisting in participation in natural creative processes. He replaces his earlier "idealist" view that reality is in itself unknowable with the "idealist realist" view that reality is knowable as creative nature, yet, in its spontaneous creativity, still eludes full comprehension. I argue that Schlegel's third approach to the re-enchantment of nature is his most consistent and satisfactory, and is important for contemporary environmental philosophy in showing how re-enchantment is compatible with modernity.