entirely subordinates the one to the other. The fate of Spinosa, with his barren union of all things in one substance, on the one hand; that of Hume, with his equally barren 'looseness and separateness' of everything, on the other,—neither philosopher owning any strict and systematic disciples to-day, each being to posterity a warning as well as a stimulus,—show us that the only possible philosophy must be a compromise between an abstract monotony and a concrete heterogeneity. But the only way to mediate between diversity and unity is to class the diverse items as cases of a common essence which you discover in them. Classification of things into extensive 'kinds' is thus the first step; and classification of their relations and conduct into extensive 'laws' is the last step, in their philosophic unification. A completed theoretic philosophy can thus never be anything more than a completed classification of the world's ingredients; and its results must always be abstract, since the basis of every classification is the abstract essence embedded in the living fact,—the rest of the living fact being for the time ignored by the classifier. This means that none of our explanations are complete. They subsume things under heads wider or more familiar; but the last heads, whether of things or of their connections, are mere abstract genera, data which we just find in things and write down.
When, for example, we think that we have rationally explained the connection of the facts A and B by classing both under their common attribute x, it is obvious that we have really explained only so much of these items as is x. To explain the connection of choke-damp and suffocation by the lack of oxygen is