§ 209. Suppose it to be granted that the categories of nature are quite self-sufficient. This would mean that there might conceivably be a strictly physical order, governed only by mechanical principles, and by the more general logical and mathematical principles. The body of physical science so extended as to include such general conceptions as identity, difference, number, quality, space, and time, is the account of such an order. This order need have no value, and need not be known. But reality as a whole is evidently not such a strictly physical order, for the definition of the physical order involves the rejection of many of the most familiar aspects of experience, such as its value and its being known in conscious selves. Materialism, in that it proposes to conceive the whole of reality as physical, must attempt to reduce the residuum to physical terms, and with no hope of success. Goodness and knowledge cannot be explained as mass and force, or shown to be mechanical necessities. [Sidenote: Truth of Psychical Relations, but Impossibility of General Reduction to Them.] § 210. Are we then to conclude that reality is not physical, and look for other terms to which we may reduce physical terms? There is no lack of such other terms. Indeed, we could as fairly have _begun_ elsewhere. Thus some parts of experience compose the consciousness of the individual, and are said to be known by him. Experience so contained is connected by the special relation of being known together. But this relation is quite indifferent to physical, moral, and logical relations. Thus we may be conscious of things which are physically disconnected, morally repugnant, and logically contradictory, or in all of these respects utterly irrelevant. Subjectivism, in that it proposes to conceive the whole of reality as consciousness, must attempt to reduce physical, moral, and logical relations to that co-presence in consciousness from which they are so sharply distinguished in their very definition. The historical failure of this attempt was inevitable. [Sidenote: Truth of Logical and Ethical Principles. Validity of Ideal of Perfection, but Impossibility of Deducing the Whole of Experience from it.]