occupied by facts which are known to us (Greek art, Roman inscriptions, mediæval monasteries). We instinctively estimate the importance of facts by the number of the documents which mention them. We forget the peculiar character of the documents, and, when they all have a common origin, we forget that they have all subjected the facts to the same distortions, and that their community of origin renders verification impossible; we submissively reproduce the bias of the tradition (Roman, orthodox, aristocratic).
In order to resist these natural tendencies, it is enough to pass in review the whole body of facts and the whole body of tradition, before attempting to draw any general conclusion.
VII. Descriptive formulæ give the particular character of each small group of facts. In order to obtain a general conclusion, we must combine these detailed results into a general formula. We must not compare together isolated details or secondary characteristics, but groups of facts which resemble each other in a whole set of characteristics.
We thus form an aggregate (of institutions, of groups of men, of events). Following the method indicated above, we determine its distinguishing characteristics, its extent, its duration, its quantity or importance.
As we form groups of greater and greater generality we drop, with each new degree of generality, those characteristics which vary, and retain those which are common to all the members of the new group. We must stop at the point where nothing is left except the characteristics common to the whole of humanity. The result is the condensation into a single formula of the general character of an order of facts, of a language, a religion, an art, an economic organisation, a society, a government, a complex event (such as