Physiology, c. x. On the Physiology of Memory, cf. Carpenter, op. cit. pp. 436-448; Ladd, op. cit. Pt. II. c. 10, §§ 15-21. Some good remarks on the Materialist theory are to be found in Professor Calderwood's Relations of Mind and Brain, pp. 272-84. On Mental Association, cf. Hamilton, On Reid, notes D**, D***. On the Validity of Memory, J. Rickaby, First Principles, Pt. II. c. vi. On Memory and Empiricism, cf. Ward, Philosophy of Theism, pp. xiv.—xvii. and 64-67. For a collection of curious anecdotes illustrating various aspects of these faculties, see Abercrombie, On the Intellectual Powers, Pt. III. sect. I.

CHAPTER XI.

SENSUOUS APPETITE AND LOCOMOTION.

IN our classification of mental activities we have marked off as standing in strongest opposition to the cognitive operations of the mind the class of states embracing appetites, desires, impulses, volitions, emotions, and the like. There is no accepted English term which accurately expresses what is common to them all. The designation active powers, employed by Reid and Stewart, ought obviously to include the intellect. Orectic faculty-the literal transcription of the Aristotelian term-is too unfamiliar. Hamilton gave currency to the epithet conative, which emphasizes the idea of effort prominent in some of these acts; whilst others prefer the title appetitive faculty. These two last names seem to us on the whole exposed to fewest objections; however, it should be borne in mind that the phenomena of appetency include not only states of yearning for absent pleasures, but also the enjoyment of gratifications attained.

The term Appetite was used in a very wide sense by medieval writers to denote all forms of internal inclination, comprehending alike the natural tendencies or affinities (appetitus naturalis) of plants and inorganic substances, which impel them towards what is suitable to their nature, and

the feelings of conscious attraction (appetitus elicitus) in sentient and rational beings. The formal object of the appetitive faculty in this broad signification is the good. Under the good is comprised, not merely the pleasant, but everything in any fashion convenient to the nature of the being thus attracted. Continued existence, felicity, development, and perfection, together with whatever is apparently conducive to these ends, are all in so far good, and consequently a possible object of appetency; whilst whatever is repugnant to them is a mode of evil, and therefore a ground for aversion or the negative activity of the same faculty.

Of conscious appetite the schoolmen recognized two kinds as essentially distinct-rational and sensitive. The former has its source in intellectual, the latter in sensuous, apprehension.1 The two faculties, however, do not act in isolation; desires and impulses in the main sensuous often embody intellectual elements, and we therefore deem it best to postpone the chief portion of our treatment of appetency to Part II. of the present book.

Modern writers commonly confine the term appetite to certain organic cravings. These arise from the physical condition of the body; they are mainly of a periodically recurrent character, and they

1 The scholastics also divided conative states into appetitus concupiscibiles and appetitus irascibiles. The appetitive side of the soul was investigated by medieval writers mainly from the standpoint of Ethics or Moral Theology. The modern branch of study known as Esthetics, the analysis of the mental states aroused by the contemplation of the beautiful and the sublime, and the dissection of our emotions, which take up so much room in psychological treatises of the present day, found little or no space in their speculations.

are essential to the preservation of the individual or the species. The chief forms usually enumerated are those of hunger, thirst, sleep, exercise, and sex. All these activities are of the lower order of mental life, and have their source in sensation. Thus hunger springs from the uneasy feelings of the alimentary canal arising from, privation of the nutriment on which its appropriate functions are exercised. The craving for sleep or physical activity is similarly awakened by fatigue or the consciousness of an accumulation of surplus energy. Besides these peculiarly organic appetites there is a tendency in all sentient beings to seek pleasure and shrink from pain in any form, and these impulses are the great protective agencies which guard the life of the individual and the race. The gregarious instinct, maternal affection, feelings of anger, jealousy, and fear, may also belong to the purely sensuous order of conscious life provided they contain no element of reflective activity, and it is in this form they are exhibited by brutes.

LOCOMOTION.-Since movement is the outcome of appetency, it may be well to say a few words on the subject here. The organic machinery of bodily motion consists of the muscles and efferent or motor nerves ramifying throughout the system. The immediate physical condition of an action is a centrifugal or outgoing impulse along these nerve-fibres. The discharges of neural energy may proceed from several causes, and according to such distinct sources movements have been classified. Certain vital actions, such as the pulsation of the heart effected by the living organism itself independently of any stimulus from without, are styled automatic. The term reflex action is

used to denote the involuntary reflexion along a motor nerve of an afferent impulse peripherally excited. It is movement in response to sensory stimuli without the intervention of any mental effort; such, for instance, is the act of coughing, or the enlargement of the iris with the diminution of light.2 Instinctive action usually implies more than merely reflex or automatic movement. It presupposes a feeling of want and an element of effort as its cause. It is, too, of a vaguely purposive character; it is at times controllable; and in general it is psychologically more complex than either of the other species of movement.

We have thus automatic action which is usually unconscious, reflex action which may be unconscious or not, but is not caused by conscious effort, and instinctive action which is the result of conscious need. The first and second classes are involuntary; the third, though not the effect of positive volition, may at times be more or less subject to voluntary regulation and inhibition. Finally, there are volitional movements which are voluntary in the fullest sense of the word. In these last the external change is the direct effect of a positive act of will. Consequently movements may be classified according to their origin, their voluntariness, and their conscious or unconscious character thus:

MOVEMENT.

(a) Automatic (unconscious and uncontrollable)

(b) Reflex (uncontrollable) {

Unconscious
Conscious

Involuntary.

Voluntary.

2 Automatic and reflex action are thus distinguished by Professor Ladd and, we believe, by the majority of physiologists. Dr. Carpenter uses these terms frequently as equivalent. He distinguishes, however, with Hartley between primary automatic, that is, those actions due to an innate or original aptitude, such as coughing, circulation, &c., and secondary automatic or habitual action acquired by exercise but otherwise presenting all the features of reflex movement, e.g. the unconscious balancing of the body when walking. Impulsive action of this secondary automatic kind is sometimes called instinctive.