In the last preceding chapter, I have examined Mr. Spencer's chief objection to the doctrine of special creations when considered in its general aspects. I now advance to the general aspects of the evolution hypothesis as applied by this philosopher to the animal kingdom. I have already suggested the appropriate answer to the claim that the derivation of the evolution hypothesis is favorable because it has originated "among the most instructed class and in these better-instructed times," and that the derivation of the other hypothesis is unfavorable because "it originated in times of profound ignorance." On this point it is unnecessary to say more. But there is a supposed "kindred antithesis" between "the two families of beliefs" to which these two hypotheses are said respectively to belong; one of which families "has been dying out," while the other family "has been multiplying." This brings into view the peculiar philosophical system of Mr. Spencer, by which he maintains "the unity of Nature," or the prevalence of a universal law of evolution, as the law which is to be discerned in remote fields of inquiry, and which "will presently be recognized as the law of the phenomena which we are here considering," namely, the phenomena of animal life. "The discovery that evolution has gone on, and is going on, in so many departments of Nature, becomes a reason for believing that there is no department of Nature in which it does not go on."[69] In considering this mode of generalization it is important to distinguish between the phenomena that are observable in those departments of Nature which include only dead or inanimate matter, and the phenomena that are peculiar to matter organized into living beings. Again: it is important to distinguish between phenomena which have been influenced by human agencies and those which can not have been affected by the power of man. Another distinction of the greatest consequence is that which divides the phenomena in question according to their relation to a moral purpose. In one class of phenomena, a moral purpose may be plainly discovered as the purpose of an intelligent causing power, which has chosen a particular means for the accomplishment of an end. In another class of phenomena, a moral purpose may not be discoverable as the end for which the existing arrangement of things was specially designed, and to which that arrangement was an indispensable means. By classifying the departments of Nature and observing their phenomena with these discriminations, we shall be able to judge of the value of Mr. Spencer's philosophical system when applied to the animal kingdom.