Society already evolved in a certain fashion, society already arrived at a certain degree of development, society already so complicated that it conceals the economic substructure which supports all the rest, has not revealed itself to the simple narrators, except in these visible facts, in these most apparent results, and in these most significant symptoms which are the political forms, the legal dispositions and the partisan passions. The narrator, both because he lacks any theoretical doctrine regarding the true sources of the historic movement, and by the very attitude which he takes on the subject of the things which he unites according to the appearances which they have come to assume, cannot reduce them to unity, unless it be as a result of a single, immediate intuition, and if he is an artist, this intuition takes on a color in his mind and transforms itself there into dramatic action. His task is finished if he succeeds in massing a certain number of facts and events in certain limits and confines over which the observer may look as on a clear perspective; in the same way, purely descriptive geography has accomplished its task, if it sums up in a vivid and clear design a concourse of physical causes which determine the immediate aspect of the Gulf of Naples, for example, without going back to its genesis. It is in this need of graphic narration that arises the first intuitive, palpable, and, I might almost say, aesthetic and artistic occasion for all those abstractions and those generalizations, which are finally summed up in the semi-doctrine of the so-called factors.