The fact that thought essentially refers to a ‘reality’ external to it in no way diminishes its purposive character.  Whether the mind is idealizing an aspect of reality (as in mathematics) or abstracting, classifying, and predicting (as in science), it is always the fact that a particular kind of reality is needed for some serious or trivial purpose which guides the operations of the thinker.  A mind which craved to embrace all or ‘any’ reality need not think; it would do better to float without discrimination upon the flux of change.  This procedure would be so absolutely antithetical to human knowing that it seems a wanton paradox on that account to treat it as the final goal of knowledge.

Actually, of course, the philosophers who claim to be devoted to pure theory follow no such course.  They deliberately choose their ideal of what is worth knowing—­e.g., ‘God,’ or ‘the unity of all things,’ or ’the laws of the universe’—­and, disregarding all other existences, they pursue the kind of reality they desire because of its religious or moral or aesthetic value.  For there could be no greater mistake than to suppose that the common antithesis between ‘reality’ and the ‘un-real’ usually means the same thing as the distinction between what ‘exists’ and what is absolutely non-existent.  On the contrary, it is usually a judgment of value.  We may say that the ‘haunted’ house is real and the ‘ghost’ is not; but as an hallucination the ghost is real enough.  Utopia is unreal for the politician, but exists as an ideal for the theorist.  The Platonist treats our physical world of sight and touch, which we think the most real of all, as a mere illusion compared to the ‘Ideas’ of his metaphysical world.  The thinker who declares he wants to know all about ‘reality’ does not mean that he wishes to investigate everything which in any sense exists, but that he wishes to know what he considers best worth knowing—­and this, of course, implies a personal valuation, a purged and expurgated extract, which will not offend his taste.  So all philosophies are, in fact, selective.  Even the more conscientious rationalists show very little anxiety to include in their intellectual scheme a knowledge of their opponents’ opinions—­indeed, they seem to think that the existence of such facts may be made dependent wholly on their will to recognize them.  An exposition of Pragmatism is for them a ‘reality’ which does not count:  it is not worth knowing about.  And this is only natural, after all.  For ‘reality,’ the object of the mind’s search, is always a selection, conceived after the likeness of the heart’s desire, the product of a human purpose.