In pronouncing a criticism upon each artist I have adopted the plan of Baillet, the author of a voluminous history of works on taste, where he does not so frequently give his own opinion as that of others. Accordingly, I have collected the various remarks of connoisseurs, which were scattered through the pages of history; but I have not always cited my authorities, lest I should add too much to the dimensions of my book;[19] nor have I regarded their opinion when they seemed to me to have been influenced by prejudice. I have availed myself of the observations of some approved critics, like Borghini, Fresnoy, Richardson, Bottari, Algarotti, Lazzarini, and Mengs; with others who have rather criticised our painters than written their lives. I have also respected the opinions of living critics, by consulting different professors in Italy: to them I have submitted my manuscript; I have followed their advice, especially when it related to design, or any other department of painting, in which artists are almost the only adequate judges. I have conversed with many connoisseurs, who, in some points, are not less skilful than the professors of the art, and are even consulted by artists with advantage; as, for instance, on the suitableness of the subject, on the propriety of the invention and the expression, on the imitation of the antique, on the truth of the colouring. Nor have I failed to study the greatest part of the best productions of the schools of Italy; and to inform myself in the different cities what rank their least known painters hold among their connoisseurs; persuaded, as I am, that the most accurate opinion of any artist is formed where the greatest number of his works are to be seen, and where he is most frequently spoken of by his fellow citizens and by strangers. In this way, also, I have been enabled to do justice to the merits of several artists who had been passed over, either because the historian of their school had never beheld their productions, or had merely met with some early and trivial specimens in one city, being unacquainted with the more perfect and mature specimens they had produced elsewhere.