their minds.
If history is not to be lost in the confusion of its materials, it must be made a rule to proceed here, as in the other sciences, by way of question and answer. But how are the questions to be chosen in a science so different from the others? This is the fundamental problem of method. The only way to solve it is to begin by determining the essential characteristic of historical facts by which they are differentiated from the facts of the other sciences.
The sciences of direct observation deal with realities, taken in their entirety. The science which borders most closely on history in respect of its subject-matter, descriptive zoology, proceeds by the examination of a real and complete animal. This animal is first observed, as a whole, by actual vision; it is then dissected into its parts; this dissection is analysis in the original sense of the word (ἁναλὑειν, to break up into parts). It is then possible to put the parts together again in such a way as to exhibit the structure of the whole; this is real synthesis. It is possible to watch the real movements which are the functions of the organs in such a way as to observe the mutual actions and reactions of the different parts of the organism. It is possible to compare real wholes and see what are the parts in which they resemble each other, so as to be able to classify them according to real points of resemblance. The science is a body of objective knowledge founded on real analysis, synthesis, and comparison; actual sight of the things studied guides the scientific researcher and dictates the questions he is to ask himself.