What Jim wrote. Even for the sonnet, this would be about as good as it gets. I love the immediacy of the initial image, instantly setting the scene, mood. Nice binding to the violence of man in L3, though the line gets into a jog-trot rhythm there which brings the rhetoric a tad into preciousness, with the "and...and"s. Were this mine, I'd replace a couple of those single-syllables with something trochaic and a comma -- "certain, swift, and savage...", etc.
Exemplary, by-the-book maneuvering at the volta, with a powerful meditation and summation on the desensitizing process of logical, loveless Nature.
To me, one of the most striking features of this poem is the brutally strong end words employed in each line -- concrete nouns almost without exception, lending extreme weight and impetus to the poem, though I also noted the perfectly balanced admixture of the physical with the emotional and abstract/intellectual elements. Amazing work.