and all synthetic operations are not necessarily better performed when they are performed by the same person; that though the characters of historian and scholar may be combined, there is nothing illegitimate in their separation; and that perhaps this separation is desirable in theory, as, in practice, it is often a necessity.
In practice, what happens is as follows. Whatever part of history a man undertakes to study, there are only three possible cases. In the first the sources have already been emended and classified; in the second the preliminary work on the sources, which has been only partially done, or not at all, offers no great difficulty; in the third the sources are in a very bad state, and require a great deal of labour to fit them for use. We may observe, in passing, that there is naturally no proportion between the intrinsic importance of the subject and the amount of preliminary work which must be done before it can be treated: there are some subjects of the highest interest, for example the history of the origin and early development of Christianity, which could not be properly attacked till after the completion of investigations which occupied several generations of scholars; but the material criticism of the sources of the history of the French Revolution, another subject of the first rank, gave much less trouble; and there are comparatively unimportant problems in mediæval history which will not be solved till after an immense amount of external criticism shall have been performed.
In the two first cases the expediency of a division of labour does not come in question. But take the third case. A man of ability discovers that the documents which are necessary for