Before saying a word as to the true importance of this point of view, we may profitably correct the commonplace idea of its nature. Materialism, in a strict philosophical sense, means the conviction that nothing is real but that which is solid, or, perhaps, which gravitates. By a not very convincing analogy from this idea, all those passions and necessities which we speak of in a quite loose and popular way as connected with the body, may be and often are regarded as “material” in opposition to energies which it seems pleasanter {29} to ascribe to incorporeal mind. But it should be noted that this secondary usage, especially in a time when no one denies the physical correlation of all psychical activity, has no important ethical implication. Like the “flesh” or the “body” of St. Paul’s religious language, the “bodily” or “material” needs and appetites of man are an element of mind, the rank and value of which must be determined on other grounds than the notion that they are connected in some peculiar degree with “physical” conditions. The economic view of history has been called and has called itself materialist partly because of the commonplace usage, which I have just described, by which certain passions and necessities, which it takes to be fundamental, are apt to be called material as opposed to ethical or ideal--a wholly unjustified opposition--and partly from the notion, which I referred to at the beginning of this chapter, that the success of political economy was in some way analogous to that of the mathematical science of abstract matter.