Man possesses two kinds of consciousness—an active, vigilant, coördinating consciousness (the seat of which is, probably, in the cortical portion of the brain) and the passive, pseudo-dormant, and, to a certain extent, incoherent and non-coördinating consciousness (the so-called sub-liminal consciousness) whose seat is in the great ganglia at the base of the brain (optic thalami and corpora striata), and in other ganglia situated in the spinal cord and elsewhere in the body. My fox terrier has a brain which, in all essential details, does not differ from that of man, and my observations teach me that his mind is the same in kind as that of man as far as memory, emotions, and reason are concerned; then why deny him the possession of abstraction in some degree? I do not mean that abstraction which enables a man to soar into realms of thought infinitely above any effort of ideation to be attained by any of the lower animals, but abstraction in its embryonic state. I am convinced, by actual experimentation, that this dog falls into "brown studies" just as man does; may he not then claim one kind of abstraction, if not another?
The elephant, unquestionably, is able to formulate abstract ideas, the quality of which is very high, indeed. Jenkins wrote to Romanes as follows:—
"What I particularly wish to observe is that there are good reasons for supposing that elephants possess abstract ideas; for instance, I think it is impossible to doubt that they acquire through their own experience notions of hardness and weight, and the grounds on which I am led to think this are as follows:—
"A captured elephant after he has been taught his ordinary duty, say about three months after he has been taken, is taught to pick up things from the ground and give them to his mahout sitting on his shoulders. Now the first few months it is dangerous to require him to pick up anything but soft articles, such as clothes, because things are often handed up with considerable force.
"After a time, longer with some elephants than others, they appear to take in a knowledge of the nature of the things they are required to lift, and the bundle of clothes will be thrown up sharply as before, but heavy things, such as a crowbar or a piece of iron chain, will be handed up in a gentle manner; a sharp knife will be picked up by its handle and placed on the elephant's head, so that the mahout may take it by the handle. I have purposely given elephants things to lift which they could never have seen before, and they were all handled in such a manner as to convince me that they recognized such qualities as hardness, sharpness, and weight."[116]
Mr. Conklin, the celebrated elephant trainer, once told me that his elephants not only recognized such qualities as weight, sharpness, and hardness, but also volume or dimension.
The kinship of mind in man and the lower animals is indicated also by the phenomenon of dreaming which is to be observed in both. When the active consciousness is stilled by slumber, subconsciousness or ganglionic consciousness remains awake, and sometimes makes itself evident in dreams. I have repeatedly observed my terrier when under dream influence, and have been able to predicate the substance of his dreams from his actions. Like man, the dog is sometimes unable to differentiate between his waking and dreaming thoughts; he confounds the one with the other, and follows out in his waking state the ideas suggested by his dreams.
This, with normal man, is always a momentary delusion; with the dog, however, it may last for some little time. Thus, I have seen my dog chase imaginary rats around my room after having been aroused while in the midst of a dream. His chagrin when he "came to himself" and saw me laughing was always strikingly apparent.
The brains of the lower animals are susceptible to the action of drugs, whose effects on them are identical with the effects noticed when the human brain is under drug influence. Alcohol, chloroform, ether, opium, strychnine, arsenic, all produce characteristic symptoms when they are introduced into the circulatory system of the lower animals. Even the very lowest animalcules give this evidence as to the kinship of nerve and ganglionic or brain elements in man and the lower animals.
I have repeatedly noticed the action of alcohol on rhizopods. When small and almost inappreciable doses were exhibited, the little creatures became lively and swam merrily through the water; but, when large doses were given, they soon became stupefied and finally died. I have seen drunken jelly-fish rolling and tacking through the alcohol-impregnated water for all the world like a company of drunkards.[117] They soon became sober, however, when they were placed in fresh water, but remained listless and inert for some time afterward.