Although Petrarch preferred Latin to Italian in the abstract, and even affected to undervalue Dante because his chief works were composed in the vulgar tongue, he acknowledged that he had missed the perfection in Latin which he was conscious of having attained in Italian. His only prose-writings with any significance for us now are the autobiographic. Some of his ethical disquisitions, however, if they had come down from classic times, would have been regarded as precious monuments of antiquity. The most important of these is the _De Remediis utriusque Fortunæ_ (1356), in two books, the first treating of the snares of prosperity, the second arming the soul against adversity. The reflections are forcibly expressed, but in themselves somewhat trite. His tract _De sua et aliorum Ignorantia_ (1361), on the other hand, abounds with energy, and gives a lively picture of the strife in his bosom between the humanistic scholar and the orthodox Christian. More vital still, at least after some pedantic digressions have been discarded, is his _Secretum, sive de Contemptu Mundi_ (1342), where the conflict in his mind between the sense of moral obligation and his passion for Laura is so depicted as to render him the prototype of Rousseau, and entitle us to derive one of the most characteristic departments of modern literature from him. He is no less the father of modern autobiography by the slight but charming sketch he has left of himself in his _Epistola ad Posteros_, prefixed to the general collection of his letters. It was a great discovery that the external circumstances of a remarkable life are not the only ones worth relating.