and more properly belongs to the Philosophy of the Practical.[1] [Sidenote: _The demand for a theory of historical facts._] The conviction that has been gained as to the necessity of the logical element, of concepts, criteria, or values, for the formation of narrative, has induced some to demand, not only that the historian should continually have clearly and firmly in mind the concepts that he employs and his intention in employing them, but that a _theory of historical factors_ or, as others call it, a _table of values,_ should be constructed, which should serve as foundation for historical narrative in general. The demand is exactly similar to that of the man who, observing that electricians or metal-founders employ physical forces, demands the construction of a physical theory to serve as the basis of industry; as if Physics did not exist and supply the basis for industry; or as if the sciences changed their nature, according to the men who employ them. The theory of historical factors, or the table of values, exists, and is called _Philosophy,_ whose precise business it is to define _universals,_ which are _factors_ and not facts, and to give the table of _values,_ which are _categories._ At the most this demand might be taken to suggest the recommendation of a popular philosophy, for the use of professional historians; but this too exists and is natural _good sense. A_ historian who entertains doubts as to the deliverances of good sense begins to philosophize (in the restricted and professional sense of the word), and once he has done this, what is called popular philosophy no longer suffices him, or serves only to make his mental condition worse, with its insufficient nourishment. Books on the teaching of history which abound in our literature of to-day are proof of this. Disquisitions as to the _predominance_ or the _fundamental_ character of this or that historical factor belong to this popular and more or less dilettante literature. In strict philosophy, such problems do not arise, or are promptly dissolved, because it is known that, since every fact of reality depends upon another fact, so also every factor, or every constitutive element of the spirit and of reality, is such only in union with other factors and elements. None of them predominates, because measures of greater or less are not used in philosophy, and none is fundamental, because all are fundamental. [Sidenote: _Impossibility of dividing history according to its intuitive and reflective elements._]