We must seek for them in the literary remains of a people. These teach us surely, even after many ages have elapsed, about the mind, belief, and thoughts of their readers. The monuments of plastic art remain, even if they were a complete contradiction against their time, their epoch, the men who ordered them, and the crowd which now regards without understanding them.[341] A book, on the contrary, has no success except as it enters into the mind of a people,--except as the ideas which it expresses are those of all the world. Each book which is published, then (like the Mosaic books among the Jews, the Korán amongst the Mussulmen), is the true expression of the mind of a race at all the periods of its existence, even were it written in a language which is no longer spoken. The best Greek and Roman works, written for men of the same blood as ourselves, have remained classical. We must understand them, even at the present day, and we do understand them, because the thoughts which animated their authors are still our own. If, on the contrary, we wish to penetrate into any foreign literature, it becomes a labour and a fatigue, we only reach it by making an abstraction of our thoughts and our ideas, by endeavouring to enter entirely, by a violent effort, into the life and feelings of another people. Languages also have been considered capable of serving as a basis for the classification of the human race. Their importance has been largely discussed, and counts numerous warm partisans.[342] At their head we may perhaps mention Latham, who wishes the ancient history of mankind to be studied by languages,[343] and agreeing in Prichard’s ideas about the production of intermediary hybrid races, he only sees this method of reading the history of the past, and he is quite naturally led to language, which seems to him to offer better conditions of resistance[344] than physical characteristics.