All scientific work is in a sense provisional, and _Domesday Book and Beyond_ contains some theories which we believe that Maitland would have subsequently revised. But whether it be regarded as a model of acute and substantial investigation, or weighed by the mass of its contributions to the permanent fabric of historical understanding and knowledge, it will assuredly rank among the classical monographs of historical science. Maitland did not profess to cover the whole field of economic and social development. He approached the history of the eleventh century mainly as a lawyer anxious to analyse the legal conceptions of that age, and fully conscious of the extreme difficulty and delicacy of his task. "The grown man," he remarks, "will find it easier to think the thoughts of the schoolboy than to think the thoughts of the baby. And yet the doctrine that our remote forefathers being simple folk had simple law dies hard. Too often we allow ourselves to suppose that, could we but get back to the beginning, we should find that all was intelligible and should then be able to watch the process whereby simple ideas were smothered under subtleties and technicalities. But it is not so. Simplicity is the outcome of technical subtlety; it is the goal not the starting-point. As we go backwards the familiar outlines become blurred; the ideas become fluid, and instead of the simple we find the indefinite.... We must not be in a hurry to get to the beginning of the long history of law. Very slowly we are making our way towards it. The history of law must be a history of ideas. It must represent not merely what people have done and said, but what men have thought in bygone ages. The task of reconstructing ancient ideas is hazardous and can only be accomplished little by little. In particular there lies a besetting danger for us in the barbarian's use of a language which is too good for his thought. Mistakes then are easy, and when committed they will be fatal and fundamental mistakes. If for example we introduce the _persona ficta_ too soon, we shall be doing worse than if we armed Hengest and Horsa with machine guns or pictured the Venerable Bede correcting proofs for the press; we shall have built upon a crumbling foundation." The main argument of the book was directed against the view that the English manorial system was the outcome of the Roman villa. The English language, the names of our English villages, were sufficient to rebut the hypothesis that the bulk of the agricultural population was of Celtic blood descended from the slaves or _coloni_ of Roman times. Romanism would give no rational explanation of the state of things revealed by the Domesday survey in the northern and eastern counties. Nor would it explain seignorial justice. It was shown that at the time of the survey England was still incompletely manorialised, that the Domesday manors varied indefinitely in size and type, that some had