The fourteenth and fifteenth books of Boccaccio's treatise, _De Genealogia Deorum_, have been called "the first defence of poesy in honor of his own art by a poet of the modern world;" but Boccaccio's justification of imaginative literature is still primarily based on the usual mediaeval grounds. The reality of poetry is dependent on its allegorical foundations; its moral teachings are to be sought in the hidden meanings discoverable beneath the literal expression; pagan poetry is defended for Christianity on the ground that the references to Greek and Roman gods and rituals are to be regarded only as symbolical truths. The poet's function, for Boccaccio, as for Dante and Petrarch, was to hide and obscure the actual truth behind a veil of beautiful fictions--_veritatem rerum pulchris velaminibus adornare._[10] The humanistic point of view, in regard to poetry, was of a more practical and far-reaching nature than that of the Middle Ages. The allegorical interpretation did indeed continue throughout the Renaissance, and Mantuan, for example, can only define a poem as a literary form which is bound by the stricter laws of metre, and which has its fundamental truths hidden under the literal expressions of the fable. For still later writers, this mode of regarding literature seemed to present the only loophole of escape from the moral objections to poetry. But in employing the old method, the humanists carried it far beyond its original application. Thus, Lionardo Bruni, in his _De Studiis et Literis_ (_c._ 1405), after dwelling on the allegorical interpretation of the pagan myths, argues that when one reads the story of AEneas and Dido, he pays his tribute of admiration to the genius of the poet, but the matter itself is known to be fiction, and so leaves no moral impression.[11] By this Bruni means that fiction as such, when known to be fiction, can leave no moral impression, and secondly, that poetry is to be judged by the success of the artist, and not by the efficacy of the moralist. Similarly, Battista Guarino, in his _De Ordine Docendi et Studendi_ (1459), says that we are not disturbed by the impieties, cruelties, horrors, which we find in poetry; we judge these things simply by their congruity with the characters and incidents described. In other words, "we criticise the artist, not the moralist."[12] This is a distinct attempt at the aesthetic appreciation of literature, but while such ideas are not uncommon about this time, they express isolated sentiments, rather than a doctrine strictly coordinated with an aesthetic theory of poetry.