All the chanceries did not turn out equally elegant documents. A leathern official style, in the impurest of Latin, was very common. In the Milanese documents preserved by Corio there is a remarkable contrast between this sort of composition and the few letters written by members of the princely house, which must have been written, too, in moments of critical importance.[534] They are models of pure Latinity. To maintain a faultless style under all circumstances was a rule of good breeding, and a result of habit. Besides these officials, private scholars of all kinds naturally had correspondence of their own. The object of letter-writing was seldom what it is nowadays, to give information as to the circumstances of the writer, or news of other people; it was rather treated as a literary work done to give evidence of scholarship and to win the consideration of those to whom it was addressed. These letters began early to serve the purpose of learned disquisition; and Petrarch, who introduced this form of letter-writing, revived the forms of the old epistolary style, putting the classical ‘thou’ in place of the ‘you’ of mediæval Latin. At a later period letters became collections of neatly-turned phrases, by which subjects were encouraged or humiliated, colleagues flattered or insulted, and patrons eulogised or begged from.[535] The letters of Cicero, Pliny, and others, were at this time diligently studied as models. As early as the fifteenth century a mass of forms and instructions for Latin correspondence had appeared, as accessory to the great grammatical and lexicographic works, the mass of which is astounding to us even now when we look at them in the libraries. But just as the existence of these helps tempted many to undertake a task to which they had no vocation, so were the really capable men stimulated to a more faultless excellence, till at length the letters of Politian, and at the beginning of the sixteenth century those of Pietro Bembo, appeared, and took their place as unrivalled masterpieces, not only of Latin style in general, but also of the more special art of letter-writing. Together with these there appeared in the sixteenth century the classical style of Italian correspondence, at the head of which stands Bembo again.[536] Its form is wholly modern, and deliberately kept free from Latin influence, and yet its spirit is thoroughly penetrated and possessed by the ideas of antiquity. These letters, though partly of a confidential nature, are mostly written with a view to possible publication in the future, and always on the supposition that they might be worth showing on account of their elegance. After the year 1530, printed collections began to appear, either the letters of miscellaneous correspondents in irregular succession, or of single writers; and the same Bembo whose fame was so great as a Latin correspondent won as high a position in his own language.[537]