BOOK II.--The unfinished second book is of the utmost value to the student of Italian poetic form. It makes us realise, too, how zealously Dante sought out technical perfection, studying subtle musical and rhythmical effects, curiously weighing the divisions of his stanzas, balancing lines, selecting words, harmonising syllables. No less noteworthy are his modest references to his own work and his generous appreciation of that of others, his predecessors and contemporaries, with reference to whose poems, as well as to his own, he illustrates his maxims. There is a certain limitation in that Dante conceives of poetry as only lyrical and written to be set to music (ii. 4), recognising only the most elaborate and least spontaneous forms of lyrical poetry--the Canzone (of which the Sestina is a variety), the Ballata, the Sonnet (ii. 3). There is no hint of that splendid rhythm, at once epical and lyrical, in which the _Divina Commedia_ was to be written; though it is possible that Dante would have dealt with it in the fourth book, in which he intended to treat the discernment to be exercised with a subject fit to be sung in the “comic” style, in which sometimes the “middle” and sometimes the “lowly” vernacular may be used (ii. 4), and also, dealing with poems in the “middle” vulgar tongue, to treat specially of rhyme (ii. 13). The third book would perhaps have been concerned with the use of the illustrious vernacular in Italian prose (ii. 1.) The illustrious vulgar tongue having been found, Dante proceeds thus to show the noblest use to which it can be put by the poet. Only three subjects are sufficiently exalted to be sung in this stateliest form of Italian speech, this highest vernacular: _Salus_, _Venus_, _Virtus_; or those things which specially relate to them: the rightful use of arms, the fire of love, the direction of the will; and the first of these themes had not been handled, according to Dante, by any Italian poet. He cites Bertran de Born as having written on arms, Arnaut Daniel and Cino da Pistoia on love, Giraut de Borneil and “the friend of Cino” (himself) on _rectitudo_ (ii. 2). Of the three legitimate lyrical forms the canzone is noblest, and contains what Rossetti called the “fundamental brainwork” of the most illustrious poets (ii. 3). And the ballata is nobler than the sonnet. It is in the canzone alone, in the “tragic” or highest style, that these sublime themes are to be sung; the style in which the stateliness of the lines, the loftiness of the construction, and the excellence of the words agree with the dignity of the subject. In this superexcellent sense, a canzone is a composition in the loftiest style of equal stanzas, without a refrain, referring to one subject.[21] And the rest of the book is occupied with rules for its proper construction; the different lines to be used, the choice of words, the structure of the various types of stanza, in which the whole