The detailed study of
the facts will require the use of lists of questions entering more into
detail, and differing according to the nature of the events, the men, or
the societies studied. In order to frame these lists, we begin by
setting down those questions or matters of detail which are suggested by
the mere reading of the documents; but for the purpose of arranging
these questions, often indeed for the purpose of making the list
complete, recourse must be had to the systematic _a priori_ method.
Among the classes of facts, the persons, and the societies with which we
are well acquainted (either from direct observation or from history), we
look for those which resemble the facts, the persons, or the societies
which we wish to study. By analysing the scheme of arrangement used in
the scientific treatment of these familiar cases we shall learn what
questions ought to be asked in reference to the analogous cases which we
propose to investigate. Of course the model must be chosen
intelligently; we must not apply to a barbarous society a list of
questions framed on the study of a civilised nation, and ask with regard
to a feudal domain what agents corresponded to each of our ministers of
state--as Boutaric did in his study of the administration of Alphonse of
Poitiers.

This method of drawing up lists of questions which bases all historical
construction on an _a priori_ procedure, would be objectionable if
history really were a science of observation; and perhaps some will
think it compares very unfavourably with the _a posteriori_ methods of
the natural sciences. But its justification is simple: it is the only
method which it is possible to employ, and the only method which, as a
matter of fact, ever has been employed. The moment an historian attempts
to put in order the facts contained in documents, he constructs out of
the knowledge he has (or thinks he has) of human affairs a scheme of
arrangement which is the equivalent of a list of questions--unless,
perhaps, he adopts a scheme which one of his predecessors has
constructed in a similar manner. But when this work has been performed
unconsciously, the scheme of arrangement remains incomplete and
confused. Thus it is not a case of deciding whether to work with or
without an _a priori_ set of questions--we must work with such a set in
any case--the choice merely lies between the unconscious use of an
incomplete and confused set of questions and the conscious use of a