sufficed to give those who have applied it the consciousness of incontestable superiority. But it is only a halfway-house between common credulity and scientific method. Here, as in every science, the starting-point must be methodical doubt. All that has not been proved must be temporarily regarded as doubtful; no proposition is to be affirmed unless reasons can be adduced in favour of its truth. Applied to the statements contained in documents, methodical doubt becomes methodical distrust.
The historian ought to distrust a priori every statement of an author, for he cannot be sure that it is not mendacious or mistaken. At the best it affords a presumption. For the historian to adopt it and affirm it afresh on his own account implies that he regards it as a scientific truth. To take this decisive step is what he has no right to do without good reasons. But the human mind is so constituted that this step is often taken unconsciously (cf. book ii. chap. i.). Against this dangerous tendency criticism has only one means of defence. We must not postpone doubt till it is forced upon us by conflicting statements in documents; we must begin by doubting. We must never forget the interval which separates a statement made by any author whatsoever from a scientifically established truth, so that we may continually keep in mind the responsibility which we assume when we reproduce a statement.
Even after we have accepted the principle and resolved to apply this unnatural distrust in practice, we tend instinctively to free ourselves from it as soon as possible. The natural impulse is to perform the criticism of the whole of an author, or at least of the whole of a