Setting aside his rhetorical and occasional compositions, the largest of which is the _De rebus gestis Antonii Caraphaei_ (Naples, Mosca, 1716), the continuation of his thought, now concentrating upon moral and historical problems, is sketched in a lecture of 1719 (of which an abstract is included in the autobiography) and developed first in 1720 in a printed prospectus of four double-columned pages known as the _Sinopsi del diritto universale,_ and secondly in the vast treatise, _De universi iuris uno principio et fine uno liber unus_ (Naples, Mosca, 1720) completed next year with the _Liber alter qui est de constantia iurisprudentis,_ and supplemented in 1722 by the _Notae in duos libros,_ etc. (same publisher); a work which is usually referred to briefly following the author's example as the _Diritto universale._ This book, according to Cantoni (_op. cit._ p. 243) represents the culminating point of Vico's scientific activity. The verdict is no more acceptable than that quoted above. The author (_Opp._ v. 10-11) rejected the _Diritto universale_ because he seemed to find persisting there the prejudice and the pretence of "descending" from the thought of Plato and other philosophers to that of primitive man, a tendency which led him astray "in certain matters"; but he also calls it, and rightly, a "sketch for the _Scienza Nuova,_" which it really is. The ideas about poetry are here still confused, Homer is not yet a myth, the mythological canons have less unity than they acquired later, the theory of reflux is only faintly adumbrated, and in a word both the ideal eternal history and the theory of knowledge upon which it is founded are as yet immature. The book is all contained, under a new form, in his later work, except the general ethical and juridical philosophy, which is not highly original, and some historical developments which are merely alluded to in the later writings. The MS. of an Italian work in two books, in which Vico expounded his doctrines "by a negative method," has been lost. But he expounds them positively and at less length in the _Principi di una Scienza Nuova intorno alla comune natura delle nazioni, per la quale si ritrovano i principi di altro sistema del diritto naturale delle genti_ (Naples, Mosca, 1725) which is known by the title (again authorised by himself) of First _Scienza Nuova._