nd feeling. CHAPTER XXIII. THE ANIMAL FACULTIES. The highest faculties of animals are different in kind from those of man. One distinct faculty (instinct) which is but very slightly developed in him is very highly developed in many animals. Movement and feeling-Reflex action-Practical intelligence of animals Movement THE functions which are peculiar to the higher organisms and are exhibited by all living creatures which possess nervous and muscular tissue, are (as has been before said) those of movement and feeling. These two functions are distinguished as those of animal life, in contradistinction to the functions of nutrition and reproduction, which, being possessed by all plants as well as animals, are termed the vegetative functions. That the animals with which we are most familiar have feelings and emotions, and that we can, to a considerable extent, tell what they are, hardly any one will be disposed to deny. No reasonable man who sees a dog frisk about with wagging tail and cheerful bark, upon his master putting on his hat, can doubt but that the dog has also seen the hat put on, and is on that account excited by pleasurable, expectant feelings. Strictly speaking, of course, no one can directly and with exactness know any feelings but his own, though speech enables us to know that our fellow-men feel and have the same faculties and the same endowments, sensitive and intellectual, that we have. Animals cannot tell us in words that they feel. Nevertheless, their mute expressions are amply sufficient to assure the common sense of mankind that many animals-e.g. a dog, a monkey, a parrot, or a frog-not only have feelings, but also, to a considerable extent, what those feelings are certainly that they can see and hear. But we have further grounds for believing that animals feel and possess sensitive faculties, similar to our own; for we have seen that function goes with structure, and we know by consciousness and observation that while our nervous system remains uninjured, diverse feelings attend the application of diverse stimuli to it. Now, seeing that birds, beasts, and other vertebrates have a nervous system more or less closely resembling our own, we may reasonably conclude that, as long as their organization is unimpaired, feelings more or less like ours will follow the application to them of stimuli like those applied to our own bodies. As to lower creatures, we find as we descend through the series of animals, an increasing divergence, in the form of their nervous system, and, on the whole, a decreasing complexity and perfection in its structure. Nevertheless, wherever we find eyes, we may conclude the creatures possessing them have some power of vision-if only a power of distinguishing between light and darkness-and wherever we find tactile organs, or appropriate movements (in uninjured organisms) in response to various forms of contact, we may conclude that there is also sensitivity. It is impossible to doubt, when watching a bee rifle a flower of its nectar, that the insect not only sees the flower but also feels those parts of it which it so dexterously explores. But we have already seen that, though other functions are ministered to by the nervous system * besides sensation, yet sensation is its especial function. We may therefore safely conclude, wherever we find any living animal which performs actions seeming to indicate the presence of sensation, and which has a nervous system intact and uninjured, that such an animal really feels. We say "intact and uninjured," because the phenomena of reflex action, which Reflex we have already noted may take place in human beings + See above, p. 167. * See above, p. 168. action. Practical intelligence gravely injured, show that we might, without such reservation, fall into error. But, indeed, our judgment that similar stimuli produce in men and animals similar normal results, is confirmed by the fact that essentially similar abnormal results occur as a consequence of analogous injuries. In animals the nervous centres of which have been injured, reflex movements of the limbs will take place, similar to those which will take place in human beings in like case. Many animals, indeed, display reflex action in a much more surprising manner-notably the frog, which deserves to be called the animal-martyr of science, from the constant recourse which is had to it for physiological experimentation. Here it is evident that the stimulus is not the cause of the reflex action, but only serves to elicit it from an organism possessing a certain vitality and spontaneity. The real cause is immanent in the mutilated organism acted on. A frog which not only has had its nervous centres injured, but has had its head cut off, will yet make with its hind legs the most appropriate movements to remove an object applied to the hinder part of its body. If its skin be touched with some caustic fluid, a leg will be quickly advanced and applied to the irritated part, and if that leg be held, then the other leg will be moved and similarly applied. But this is not all at the breeding season the male frog tightly grasps the female behind her arms, and, to enable him the more securely to maintain his hold, a warty prominence is then developed on the inner side of each of his hands. Now, if such a male frog be taken, and not only decapitated, but the whole hinder part of the body also removed, so that nothing remains but the fragment of the trunk from which the two arms with their nerves proceed, and if under these circumstances the warty prominences be touched, the two arms will immediately close together like a spring. Evidently, then, we can arrive at no trustworthy conclusions except by observations with respect to animals the organization of which is intact. That animals have not only special senses and general of animals. sensitivity, but also much practical intelligence, is a fact which no sane mind can doubt. They show plainly enough that they can thus appreciate (ie. practically) very abstract matters, such as motion, number, cause, solidity, etc., and can attend to and classify objects in various appropriate categories according to their several properties. As to motion, a cat which runs after a mouse, or even a pike which overtakes and catches a small fish, shows by its actions that it possesses a practical knowledge of what motion is; as does a dog which scuttles hastily out of the reach of a stone thrown after it. A dog may also show that it practically recognizes "number," when two friends simultaneously call it in two different directions. Not merely such a very highly-organized animal, however, but even an insect will discriminate between objects. which differ in number-between an attack by one enemy on one side of it, and a simultaneous attack by two enemies, one on either side of it; between one object of pursuit and several objects of pursuit—and will regulate its responsive movements accordingly. A dog, startled at the agitation. by the wind of an expanded parasol lying near it on a grass-plot, may, by its angry growl, show its apprehension of some hidden, possibly hostile, cause of such motion; and it may show not only its appreciation of a cause, but of causes of different orders, when the raising of a latch may lead it first to display an excitement of expectation, to be followed by discriminating gestures, according as he who raises the latch may prove to be the dog's master, a known visitor, or a suspicious-looking stranger. An elephant will hesitate to cross a bridge it seems to feel insecure, thus showing in one way that it has a distinct and practical apprehension of the abstract quality, "solidity," as a hyæna making an extra effort to crush a very hard bone, shows it in another way. Animals, again, readily vary their conduct according to the properties of objects presented to their senses, i.e. they recognize, draw practical inferences,† and, as before said, classify. A cat will make use of visible characters as a basis of its system of classification. A dog divides the material universe, organic and inorganic, into groups and sub-groups according to a finely graduated series of smells. * See above, pp. 95, 191, 192. † See above, pp. 94, 194, 195. Animals of the most varied kinds, from insects to apes, will, as their actions prove, anticipate, from signs which they recognize, the presence in objects of characters and tendencies to action as yet unperceived. A monkey will show a practical dread of the hurtful properties of a viper, and a wasp, a similar appreciation of the luscious sweetness hidden beneath the skin of the ripe fruit it attacks. Insects, indeed, present us with wonderful phenomena of an intelligent nature. Ants display a complete and complex political organization, classes of beings socially distinct, war resulting in the capture of slaves, and the appropriation and maintenance of domestic animals (Aphides) analogous to our milk-giving cattle. Moreover, animals practically apprehend universals,* for a sheep does not dread a particular wolf, but any wolf-" wolf in general." Can we, then, attribute to animals an intelligence such as our own, but inferior in amount-alike in kind, and differing only in degree? Before seeking a reply to this question, it may be well for the reader to carefully reperuse the fourteenth chapter of this work, in order to realize how rich are the sensitive faculties, and how numerous and complex are the practical cognitions possible even in man, without the exercise of intellect. All those varied sensitive powers, with the corresponding bodily activities, are unquestionably possessed by the higher animals as well as by man; and if those animals do not possess the higher faculty of intellect, then it may well be that, such sensitive faculties (having the whole field of life, as it were, to themselves), may energize more vividly and perfectly in animals than they can do in us where they are so commonly interfered with by the action of the intellect. But some readers may be inclined to impatiently protest that animals are without question highly intelligent, that many of them know their homes, their friends, and their enemies; that, therefore, animals "know" many things which we know, and that though they have not the use of words, they must, at least, have "ideas," and therefore a true intelligence. Now, most certainly animals have "intelligence," "understanding,” and *See above, p. 206. + See above, p. 178. As to the various meanings of the word "know," see above, p. 189. |