In 1725, the year of the publication of the first _Scienza Nuova,_ Vico related the history of his studies: _Vita di G. B. Vico scritta da se medesimo,_ which was inserted in Calogerà's _Raccolta di opuscoli scientifici e filologici_ (Venice, Zani, 1728, vol. i. pp. 145-256). Among the minor writings of this period may be noted the two speeches on the death of the Countess of Althann (1724) and the Marchesana della Petrella Angiola Cimini (1727); the little volume _Vici vindiciae_ (Naples, Mosca, 1729) containing a personal defence (together with an important theoretical digression on "laughter") against a malevolent notice inserted in the _Acta Lipsiensia_ of 1727, about the _Scienza Nuova;_ and some fine letters to Giacchi, Degli Angioli, Esperti, De Vitry and Solla on the contrast between his works and the state of learning at this time. To the first _Scienza Nuova_ Vico thought of adding a long series of _Annotations_ in a reprint of it which he was preparing at Venice between 1728 and 1730. But since this scheme was not carried out, and on the other hand he was dissatisfied with the book not so much on account of the matter, he says, as on account of the arrangement (_Opp._ vi. 11), he resolved to publish an entirely new exposition of his doctrines in the _Cinque libri de' principi di una Scienza Nuova d'intorno alla comune natura delle nazioni, in questa seconda impressione con più propia maniera condotti e di molto accresciuti_ (Naples, Mosca, 1730), which form the second _Scienza Nuova._ While Cantoni (_op. cit._ pp. 238-9) considers this work the dotage of Vico's thought, it is really the necessary result and perfect form in which his previous attempts issued; it is the book which with the _De antiquissima_ and the autobiography supplies all the necessary material for a knowledge of his thought. In the _Diritto universale_ and the first _Scienza Nuova_ we can find a few details omitted in the later work; but those treatises display the same doctrines as the second _Scienza Nuova_ in a manner much less profound and solid, and certainly less characteristic of the author. The detailed comparison of these three works has been made with great care in the short summaries added by Ferrari to his editions of the first and second _Scienza Nuova._