The _Convito_ is also imperfect. It was to have consisted of fourteen treatises, but, as we have it, contains only four. In the first he justifies the use of the vulgar idiom in preference to the Latin. In the other three he comments on three of his own _Canzoni_. It will be impossible to give an adequate analysis of this work in the limits allowed us.[62] It is an epitome of the learning of that age, philosophical, theological, and scientific. As affording illustration of the _Commedia_, and of Dante's style of thought, it is invaluable. It is reckoned by his countrymen the first piece of Italian prose, and there are parts of it which still stand unmatched for eloquence and pathos. The Italians (even such a man as Cantù among the rest) find in it and a few passages of the _Commedia_ the proof that Dante, as a natural philosopher was wholly in advance of his age,--that he had, among other things, anticipated Newton in the theory of gravitation. But this is as idle as the claim that Shakespeare had discovered the circulation of the blood before Harvey,[63] and one might as well attempt to dethrone Newton because Chaucer speaks of the love which draws the apple to the earth. The truth is, that it was only as a poet that Dante was great and original (glory enough, surely, to have not more than two competitors), and in matters of science, as did all his contemporaries, sought the guiding hand of Aristotle like a child. Dante is assumed by many to have been a Platonist, but this is not true, in the strict sense of the word. Like all men of great imagination, he was an idealist, and so far a Platonist, as Shakespeare might be proved to have been by his sonnets. But Dante's direct acquaintance with Plato may be reckoned at zero, and we consider it as having strongly influenced his artistic development for the better, that transcendentalist as he was by nature, so much so as to be in danger of lapsing into an Oriental mysticism, his habits of thought should have been made precise and his genius disciplined by a mind so severely logical as that of Aristotle. This does not conflict with what we believe to be equally true, that the Platonizing commentaries on his poem, like that of Landino, are the most satisfactory. Beside the prose already mentioned, we have a small collection of Dante's letters, the recovery of the larger number of which we owe to Professor Witte. They are all interesting, some of them especially so, as illustrating the prophetic character with which Dante invested himself. The longest is one addressed to Can Grande della Scalla, explaining the intention of the _Commedia_ and the method to be employed in its interpretation. The authenticity of this letter has been doubted, but is now generally admitted.