It is clear from Guicciardini's autobiographical memoirs that he was ambitious, calculating, avaricious and power-loving from his earliest years; and in Spain he had no more than an opportunity of studying on a large scale those political vices which already ruled the minor potentates of Italy.
Yet Guicciardini's conscience accused him, for he had previously counselled the pope to declare war, as he notes in a curious letter to himself written in 1527 (Op. fined., x.
Varchi, Nardi, Jacopo Pitti and Bernardo Segni are unanimous upon this point; but it is only the recent publication of Guicciardini's private MSS.
Notwithstanding these defects, inevitable in a writer of Guicciardini's temperament, the Storia d'Italia was undoubtedly the greatest historical work that had appeared since the beginning of the modern era.
To these may be added a series of short essays, entitled Discorsi politici, composed during Guicciardini's Spanish legation.
A complete and initial edition of Guicciardini's works is now in preparation in the hands of Alessandro Gherardi of the Florence archives.