floating aphorism

Each line of the poem threatened to float off as aphorism dissipating in the atmosphere.

conditions favorable to life

Like a habitable planet a good poem should have an atmosphere and weather.

phrasally compounded

Phrases, rather than clauses, must be the units of expression. This was Blake’s mode of choice in most of his work, from The French Revolution through Jerusalem.

[…] Sentences were more phrasally compounded, less clausally complex than ever before or since. Nouns and adjectives, in natural consequence, strongly dominated verbs and took over verb meanings. Sounds, like sentences, stressed not limits, periods, bounds, and conclusions as regular feet, line forms, rhymes, and stanzas would do, but rather interior units and correspondences, in echo and onomatopoeia. Reference stressed the objects and qualities of such sensory concern, the scenes, atmospheres, and feelings which could be onomatopoetized, the natural and human items of emotional description with their minor and parallel actions of observation and acceptance.

We may think Blake as too active, rebellious, and eccentric to use such material; yet we find it basically his. What additions he made to it were…not so much changes as extensions of the basic material. He increased the characteristic reference to color, scope, and feeling; he increased human anatomizing, scenic atmosphere, and passive and expressive verbs. He used a fuller load of substantives and descriptive declaration, and a freer play of interior sound. He liked what he had, and carried it further in its own realm.

—Josephine Miles, Eras and Modes In English Poetry (U. of California Press, 1957)

gravitational force

Its atmosphere may be poetically alluring in and of itself, but content is the gravitational force of a great poem.