Nature
Hegel (philosophy of nature, comes after Logic)
Nature is the otherness of the idea --- the idea in external form. After the Logic (pure conceptuality), the idea releases itself into nature: space, time, matter, movement. Nature is not creation from nothing, but self-externalization of the logical idea. It is the idea "outside itself" --- spatially side-by-side (space), temporally one-after-another (time), mechanical, physical, organic. Nature develops from mechanics through physics/chemistry to life. In life the idea returns to itself: the organism is purpose for itself. The highest form of nature (life) turns over into spirit. Nature is a necessary passage-stage: the idea must externalize itself in order to return to itself as spirit. "Nature is spirit in its alienation."
Origin
Greek physis (nature as becoming). Aristotle: nature as the principle of movement. Kant: nature under laws. Schelling: philosophy of nature (nature as visible spirit). Hegel: nature as a moment in the system --- otherness of the idea.
In Hegel
Enc. §245-376 (Philosophy of Nature)