THE CONCEPTION OF THE ANIMAL MIND The opinions as to what is meant by the conception of mind are very divergent. Many investigators (Hackel, Famynzin, Bechterew, Claparecle, and others) are of the opinion that animal psychology must assume a mind in all animals, even the lowest. According to the view of many modern authors, animal psychology is the science of animal reflexes, instincts, plastic behaviour, and the co-ordination of these actions. Others again consider the capacity for learning, associative memory, as a proof of the presence of mental phenomena. At the root of many of these views lies the thought that the mind is a factor regulating the organic being, that it intervenes in the causal connections between material physiological phenomena. The mind is supposed to be super-added to organisms, and hence to be super-imposed on the laws of physics and chemistry applicable in lifeless nature. The mind is supposed to intervene as a factor directing events towards the attainment of definite ends and purposes, a finalist, teleologi cal principle added to the causal laws of nature. It is especially the purposefulness of animal behaviour, observable everywhere, which is the reason for this assumption. Frequently the name of "consciousness" is given to a mind so conceived, or to the sum total of the phenomena corresponding to such a mind. It leads to misunderstandings when some authors identify the object of animal psychology with the study of consciousness, while others use the conception of consciousness in the sense explained above as a "psychic factor." We here use mind as identical with con sciousness or the totality of inner experience. Everyone knows this changing play of conscious phenomena arising out of his own personal experiences. For this reason there can be no definition of the conception. With all phenomena of consciousness, physiologi cal processes occur in the central nervous system which are indissolubly bound up with them. The physiological processes in question cannot take place without the accompaniment of mental phenomena. And mental phenomena never appear without cor responding physiological changes going with them. The course of the physiological processes is continuous. The phenomena of consciousness are discontinuous, being interrupted by unconscious ness, sleep, or fainting. On this view an intervention of the mind
in the course of physiological occurrences is impossible. Further the psyche, soul or mind, is not a substance, as has sometimes been supposed, but it is a course of mental events. From all this it follows, as already indicated, that the mind cannot be objec tively experienced. No other course remains open to us, then, but to see in animals a mind analogous to our own conscious ness, and to attempt to picture to ourselves what sort of knowledge animals can obtain through the functioning of their sense organs of the things and happenings in their environment and how in consequence the world may appear to them.
The Surrounding-world and Inner-world of Animals.— For the lowest animals stimuli alone exist. The whole manifold en vironment surrounding us does not exist for them. Hence they are ignorant of enemies or dangers. The capacity to choose be tween different reactions is almost wholly lacking to these animals. Their reactions to external stimuli are fixed reflexes. In many instances this is so striking, as for example with the echinoderms, that the animals might rightly be called reflex automata. It is in just these animals that a unified central nervous system is absent. Hence their bodies cannot receive any directed stimuli. In the worms the development of a brain commences, and in higher groups this more and more takes over the co-ordination and direc tion of movements. The spontaneous movements likewise derive from this brain. The sense-organs become more and more com plex. In the most highly developed molluscs, the cephalopods, the structure of the nerve centres and with them the behaviour, is so complicated that one can credit them with a counter-world (Gegenwelt), with schemata. The brain of the arthropods is the highest switch-centre and the organ of inhibition. In the higher Crustacea associative memory appears clearly for the first time. Behaviour based on reflexes and instincts can now be modified, for the instincts are plastic up to a certain point. The surround ing-world (Umwelt), although certainly not yet objectively per ceived, becomes nevertheless ever more and more manifold. In insects these faculties become even further enhanced. Reactions to colours and to shapes exist. Nevertheless instincts still heavily outweigh plastic actions.