Philosophy, indeed, despite its apparent variety, is conservative, constant, pertinacious. Philosophy is like a romantic old lady who to the day of her death cherishes the dream of her girlhood: the dream of reducing all things to one single thing, of denying all differences and all distinctions—that is, frankly, of annihilating things. The philosopher desires to see the world issue and unfold, like a gigantic plant, from one single seed; or seeks to trace all appearances of variation back to some vague primordial mystery wherein reason may find a certain pleasure, though sense be lost.
Thus from Thales to the latest Germanic Weltanschauung the constant philosophic tendency has been to make reality illusory and to make the illusion real—that is, to sacrifice variety to oneness, the particular to the universal. And Spencer, though his acquaintance with the history of philosophy was very limited, moved in the same way. Setting aside the unknowable—established as a category for several compelling reasons, but chiefly in order to escape an embarrassing dualism—he took the knowable in hand in the endeavor to reduce it to one single principle. Force, and to one single law, Evolution. His point of departure was the homogeneous. From the homogeneous, that is, from the unique, everything is derived, everything has unfolded. All that which to us seems varied, diverse, heter-
