Georg Wilhelm Friedrich Hegel – Encyclopedia of the Philosophical Sciences, part ii (1817)

The more thought enters into our representation of things, the less do they retain their naturalness, their singularity and immediacy. The wealth of natural forms, in all their infinitely manifold configuration, is impoverished by the all-pervading power of thought, their vernal life and glowing colours die and fade away. The rustle of Nature’s life is silenced in the stillness of thought; her abundant life, wearing a thousand wonderful and delightful shapes, shrivels into arid forms and shapeless generalities resembling a murky northern fog.

* This passage is from the zusatz following §246; I’ve read that these Zusätze are editors’ additions of notes students took from Hegel’s lectures, in which he expanded on the topics from the main text.