The Cambridge History of English and American Literature in 18 Volumes (1907–21).
Volume IV. Prose and Poetry: Sir Thomas North to Michael Drayton.
§ 23. Shakespearean Blank Verse: management of metre, pause, trisyllabic substitution and the redundant syllable
But the third peculiarity which distinguishes the accomplished blank verse of Shakespeare is the most important of all. It is the mastery—on good principles of English prosody from the thirteenth century onwards, but in the teeth of critical dicta in his own day and for centuries to follow—of trisyllabic substitution. By dint of this, the cadence of the line is varied, and its capacity is enlarged, in the former case to an almost infinite, in the latter to a very great, extent. Once more, the decasyllabic norm is kept—is, in fact, religiously observed. But the play of the verse, the spring and reach and flexibility of it, are as that of a good fishing-rod to that of a brass curtainpole. The measure is never really loose—it never in the least approaches doggerel. But it has absolute freedom: no sense that it wishes to convey, and no sound that it wishes to give as accompaniment to that sense, meet the slightest check or jar in their expression.
In the latest division, one of the means of variation which had been used even before Shakespeare, and freely by him earlier, assumes a position of paramount and, perhaps, excessive importance, which it maintains in successors and pupils like Fletcher, and which, perhaps, carries with it dangerous possibilities. This is what is sometimes called the feminine, or, in still more dubious phrase, the “weak,” ending; but what may be better, and much more expressively, termed the redundant syllable. That, with careful, and rather sparing, use it adds greatly to the beauty of the measure, there is no doubt at all: the famous Florizel and Perdita scene in The Winter’s Tale is but one of many instances. But it is so convenient and so easy that it is sure to be abused; and abused it was, not, perhaps, by Shakespeare, but certainly by Fletcher. And something worse than mere abuse, destruction of the measure itself, and the substitution of an invertebrate mass of lines that are neither prose nor verse, remained behind.
But this has nothing to do with Shakespeare, who certainly cannot be held responsible for the mishaps of those who would walk in his circle without knowing the secrets of his magic. Of that magic his manipulation of all verse that he tried—sonnet, stanza, couplet, lyric, what not—is, perhaps, the capital example, but it reaches its very highest point in regard to blank verse. And, after all, it may be wrong to use the word capital even in regard to this. For he is the caput throughout, in conception and in execution, in character and in story—not an unnatural, full-blown marvel, but an instance of genius working itself up, on precedent and by experiment, from promise to performance and from the part to the whole.