regarded as purely physiological and unconscious reactions to environmental changes. A typical experiment will illustrate the nature of the evidence collected, and will serve, at the same time, to contrast the results of the experimental method with the results of simple observation. Huber, an enthusiastic observer of the habits of ants, noted that an ant which is taken from a nest and returned to it after an interval of four months is recognized and received by its former companions with all marks of friendliness. Huber considered that this was good proof of the accuracy and permanence of the ant memory. Bethe, however, took an ant from a strange nest, dipped it in a mess of impounded "home" ants, and found that the disguised stranger was received with every token of recognition and hospitality! The entire process of "recognition" is thus explicable on the ground of a chemo-reflex. We shall see presently how this and similar results are to be reconciled with those which tell strongly for the existence of mentality in the lowest forms of animal life.
Let us now turn our attention to the outcome of the experimental method as applied to higher forms, such as dogs, cats, rats, and chicks. In general, the animals are confined in cages, while appeal is made to their intelligence, ingenuity, and memory through the avenue of hunger. The results have been such as considerably to decrease our estimate of the mental capacity of the animals. Thus Thorndike, after tracing the formation of associations in the animal consciousness, remarks that his work "has rejected reason, comparison or inference, perception of similarity, and imitation. It has denied the existence in animal consciousness of any important stock of free ideas or impulses, and so has denied that animal association is homologous with the association of human psychology." A vigorous protest against this mode of interpretation has, it is true, been entered by Mills, who contends that confinement in cages is essentially an artificial and abnormal condition, that hunger is not the strongest possible means of appeal to animal intelligence, and that "it seems more probable that the mental processes of the highest animals are not radically different from those of man, so far as they go, but that the human mind has capacities in the realms both of feeling and intellection to which animals cannot attain." The general trend of opinion is, apparently, for Thorndike and against Mills; but, in face of the divergence of expert judgments, the layman will do well to hold himself in suspense, until such time as community of investigation has brought about a substantial agreement on the main points at issue. The recent publication (Kline) of a laboratory course in comparative psychology is a hopeful sign.
To return to the main problem: we have to show how the reflex and, to all appearances, wholly unconscious reactions of such forms as ants and bees are to be squared with the evidence of mentality in the protozoa, evidence which makes mind coeval with life. It seems reasonable to adopt the view which sees in impulse (the consciousness accompanying action upon presentation; see Action.) the original and primitive type of consciousness. Now, the impulse has varied in two directions. In the first place, by the gradual effacement of its distinctively mental features, the primitive type of action has come to take the form of the reflex, a relatively simple mechanical answer to stimulation. Here, in the light of Jennings's observations, we must place paramecium. In the second place, the impulsive action has, in certain forms of organic life, broadened out into selective and volitional action. Mentality has grown more complex, as in the other direction it has died out. In this line of development stand the higher animals, including man. Lastly, the most developed forms of action exhibit a constant tendency to become automatic; so, e.g., piano playing. bicycle riding. In other words, there is a tendency for certain phases of complex psycho-physiological activity to degenerate into activity which is simply physiological. The final outcome is, therefore, the formation of a system of reflexes which, in view of their circuitous development, we may term secondary reflexes. Ants and bees, as they appear in Bethe's pages, would then be types in which practically every vestige of a once fairly complicated mental structure has disappeared, to make way for an elaborate series of secondary reflexes. Thorndike has even argued, in similar vein, that the present anthropoid apes may be mentally degenerate; that their chattering is possibly "a relic of something like language," and not a first attempt at language-making.
Bibliography. Binet, The Psychic Life of Micro-Organisms (New York, 1894); Darwin, Origin of Species (London, 1859; New York, 1901); Descent of Man (London, 1871; New York, 1901); Lubbock, Ants, Bees, and Wasps (New York, 1882); Morgan, Animal Life and Intelligence (Boston, 1891); id., Habit and Instinct (London, 1896); Romanes, Animal Intelligence (New York, 1883); id., Mental Evolution in Animals (London, 1883): Wundt, Human and Animal Psychology, translated by Creighton and Titchener (New York, I896).
ANIMALS, Cruelty to. See Cruelty to Animals.
ANIMAL WOR'SHIP. See Man, paragraph Sophiology.
AN'IMA MUN'DI (Lat. the soul of the world). The view that all the changes in phenomena are due to the operation of conscious beings, conceived on the analogy of human consciousness, was the result of one of the most primitive and most naïve attempts to solve the problems presented by chance and change to experience. (See Mythology.) When the step was taken from a belief in a multiplicity of presiding genii to a single ordering consciousness, which stands in the same relation to the world as a whole as the human mind stands to the human body, the doctrine of the anima mundi was reached. It has been held in various forms, and has survived to quite recent times. Anaxagoras (q.v.), who believed in a universal reason that gave form to the universe, was one of the first Occidental philosophers who held this doctrine. Aristotle (q.v.) escaped animism (i.e., the doctrine of an anima mundi) by holding that although Nature is a being in itself alive, God is separated from nature as a transcendent spirit. In the system of the Stoics the anima mundi was conceived to be the sole vital force in the universe; it usurped the office of pure spirit, and the doctrine became indistinguishable from pantheism. In modern times Agrippa of Nettesheim (1486-1535) revived the doctrine with a changed terminology, substituting spiritus mundi for anima mundi. Bruno, Paracelsus, Sebastian
