He theorized out his art in detail and referred to his lines as apparently "lawless at first perusal, although on closer examination a certain regularity appears, like the recurrence of lesser and larger waves on the sea-shore, rolling in without intermission, and fitfully rising and falling." His feeling,--and this is the right word for a question of artistic form, which should not be determined primarily by the intellect,--his feeling was that the idea which is being expressed should govern from moment to moment the form into which it is cast, since any pattern imposed on a long poem must handicap freedom. In many a descriptive passage there is a succession of nice adjustments of word and rhythm to the thing being described. The flight of birds, the play of waves, the swaying of branches, the thousandfold variations of motion, are easy to reproduce and easy to perceive, but Whitman went far beyond these to the innate suggestions of things and of ideas. At the same time--not to be occupied in a search for variety which becomes merely chaos--he adopted a succession of pattern rhythms, taking a simple, free measure and modifying it in the reiterative form frequently used by Emerson and common to "Hiawatha." There was some acumen in Mrs. Whitman's comparison, for Longfellow's assumption of "frequent repetitions" was a reverting to the parallelism that prevails in most folk poetry, the same parallelism which is the warp of Whitman's patterns. Whitman was just as conscious in his choice of diction as in his selection of measures. Poetry, he agreed with Wordsworth, was choked with outworn phrases; the language of the people should be the source of a poetic tongue. From this he could evolve a "perfectly clear, plate-glassy style." In execution he was, of course, uneven. He wrote scores upon scores of passages that were full of splendor, of majesty, of rugged strength, of tender loveliness. In general it is true that the lines which deal with definite aspects of natural and physical beauty are most effective--lines of which "Out of the Cradle Endlessly Rocking" are the purest type; but many of the poems and sections in which concrete imagery is summoned to the explication of a general idea are often finely successful--as in his stanzas on the poet, or on himself, "the divine average," for example: My foothold is tenon'd and mortis'd in granite; I laugh at what you call dissolution; And I know the amplitude of time.