Hopkins invented "sprung rhythm" and a technique of compressed consonantal music ("the achieve of, the mastery of the thing!") that had no precedent in English. His packed, hyphenated, internally rhyming lines sound unlike anything written before or since. He published almost nothing in his lifetime; Robert Bridges released his poems 29 years after his death, and they detonated. Every 20th-century poet from Auden to Heaney felt their impact.

The case for it, the case against, and the rest of the canon open with Pro.