It is in such discussions that is to be found the true contribution of that epoch, not to learning, but to the formation of the science of Æsthetic. The ground was prepared and enriched through the work of the interpreters and commentators of Aristotle and of the new writers on Poetics, especially the Italians, and it was also enriched with some seed that was destined to sprout and to become a vigorous plant in the future. The study of Plato also contributed not a little to call attention to the function of the idea, or of the universal, in poetry. What meaning was to be attached to the statement that poetry should aim at the universal and history at the particular? What was the meaning of the proposition that poetry should proceed according to _probability_? What could that _certain idea_ consist of, which Raphæl said that he followed in his painting? [Sidenote: _Fracastoro._] Girolamo Fracastoro was among the first to ask himself this question seriously, in the dialogue _Naugerius, sive De poetica_ (1555). He disdainfully rejected the thesis that the end of poetry is pleasure: far be from us, he exclaimed, so bad an opinion of the poets, who the ancients said were the inventors of all the good arts. Nor did the end of instruction seem to him to be acceptable, which is the task, not of poetry, but of other faculties, such as geography, history, agronomy, philosophy. The poet's task is to represent or to imitate, and he differs from the historian, not in the matter, but in the manner of representation. The others imitate the particular, the poet the universal: the others are like the painters of portraits, the poet produces things as he contemplates the universal and most beautiful idea of them: the others say only what they need to say for their purposes, the poet that he may say everything beautifully and fully. But the beauty of a poem must always be understood as relative to the class of subject of which it treats; it is the most beautiful in this class, not the supremely beautiful: one must be careful to guard against the equivocal or double meaning of this word "beauty" (_æquivocatio illius verbi_). A poet never utters what is false or expresses what does not exist, for his words inevitably harmonize in appearance or signification either with the opinions of men or with the universal. Nor can we accept the Platonic axiom that the poet has no knowledge of the things of which he treats; he does know them, but in his own poet's manner.[28] [Sidenote: _L. Castelvetro._]