To a new work, then, so much more extensive than the former, I prefix a preface almost entirely new. The plan is not wholly my own, nor altogether that of others. Richardson[7] suggested that some historian should collect the scattered remarks on art, especially on painting, and should point out its progress and decline through successive ages. He has not even omitted to give us a sketch, which he brought down to the time of Giordano. Mengs[8] accomplished the task more perfectly in the form of a letter, where he judiciously distinguished all the periods of the art, and has thus laid the foundations of a more enlarged history. Were I to follow their example, the chief masters of every school would be considered together, and we should be under the necessity of passing from one country to another, according as painting acquired a new lustre from their talents, or was debased by a wrong use of the great example of those artists. This method might be easily pursued, if the subject were to be treated in a general point of view, such as Pliny has considered and transmitted it to posterity; but it is not equally adapted to the arrangement of a history so fully particular as Italy seems to require. Besides the styles introduced by the most celebrated painters, such infinite diversities of a mixed character, often united with originality of manner, have arisen in every school, that we cannot easily reduce them to any particular standard: and the same artists at different periods, and in different pictures, have adopted styles so various, that at one time they appear imitators of Titian, at another of Raffaello, or of Correggio. We cannot, therefore, adopt the method of the naturalist, who having arranged the vegetable kingdom, for example, in classes more or less numerous, according to the systems of Tournefort or of Linnæus, can easily reduce a plant, wherever it may happen to grow, to a particular class, adding a name and description, at once precise, characteristic, and permanent. In a complete history it is necessary to distinguish each style from every other: nor do I know any more eligible method of performing this task, than by composing a separate history of each school. In this I follow Winckelmann, the best historian of ancient art in design, who specified as many different schools as the nations that produced them. A similar plan seems to me to have been pursued by Rollin, in his History of Nations, who has thus been enabled to record a prodigious mass of names and events within the compass of a few volumes, in the clearest order.