With calm courage he returned to his poverty and his favourite studies, and in 1725 published the first edition of the work that forms the basis of his renown, Principii d'una scienza nuova.
In 1730 he produced a second edition of the Scienza nuova, so much altered in style and with so many substantial .additions that it was practically a new work.
This problem he proceeded to develop in various works, until in his Scienza nuova he arrived at a more complete solution, which may be formulated as follows: If the principle of justice and law be one, eternal and immutable, why should there be so many different codes of legislation?
As already stated, the Scienza nuova appeared in three different editions.
One book of the second edition of the Scienza nuova is devoted to "The Discovery of the True Homer."
Therefore, although the Scienza nuova cannot be said absolutely to deny the law of progress, it must be allowed that Vico not only failed to solve the problem but even shrank from attacking it.
At the beginning of the 19th century, however, some Neapolitan exiles at Milan called attention to the merits of their great countryman, and his reinstatement was completed by Michelet, who in 1827 translated the Scienza nuova and other works with a laudatory introduction.
The foundations of this theory of history as an upward progress of man out of a barbaric and animal condition were laid by Vico in his celebrated work Principii di scienza nuova.
His principal works are contained in four volumes comprised under the general title Filosofia dello spirito: (1) Estetica come scienza dell' espressione e linguistica generale, (2) Logica come scienza del concetto puro, (3) Filosofia della practica: economia ed etica and (4) Teoria e storia della storiografia.
The philosophers from whom Croce learned most are Vico, the author of the Scienza nuova, and Hegel, but the thought of all other thinkers flows in his writings, in conformity with its historical character, and for this reason may, for instance, be found in it traces of some of Hegel's most active opponents, such as Herbart.