did the author perform these operations correctly or not? The question may be approached on two sides.
(1) The critical investigation of authorship has often taught us the general conditions under which the author operated. It is probable that some of these influenced each one of the operations. We ought therefore to begin by studying the information we possess about the author and the composition of the document, taking particular pains to look in the habits, sentiments, and personal situation of the author, or in the circumstances in which he composed, for all the reasons which could have existed for incorrectness on the one hand, or exceptional accuracy on the other. In order to perceive these reasons it is necessary to be on the lookout for them beforehand. The only method, therefore, is to draw up a general set of questions having reference to the possible causes of inaccuracy. We shall then apply it to the general conditions under which the document was composed, in order to discover those causes which may have rendered the author's mental operations incorrect and vitiated the results. But all that we shall thus obtain—even in the exceptionally favourable cases in which the conditions of origin are well known—will be general indications, which will be insufficient for the purposes of criticism, for criticism must always deal with each separate statement.
(2) The criticism of particular statements is confined to the use of a single method, which, by a curious paradox, is the study of the universal conditions under which documents are composed. The information which is not furnished by the general study of the author may be sought for by a consideration of the necessary processes of the human mind; for,