We have, as things are, two principal methods for the study of affection: the method of impres sion and the method of expression. The former We owe to Fechner (q.v.) the latter to the Italian physiologist A. :Mosso. ( 1 The method of impression in its original form is also known as the serial method or the method of selection. (See „EsTitElacs. EXPERIMENTAL.) A long series of graded stimuli (colors, textile fabrics, ovals, or crosses) is laid before the observer. who notes his preference for particular terms in the series. From these preferences a curve may be construct ed, showing the relative feeling-value of dull and brilliant colors, of rough and smooth su• faces, etc. In its later form, the method is known as that of paired comparisons. The stim uli are here presented to the observer two at a time, so that every term in the series is com pared with every other term. The experimenter records the number of preferences that each term receives, and a curve is platted from the results. It is found, e.g., in work with colored impressions that saturated colors (red. blue) are as a rule preferred to unsaturated (pink, brown, sky blue, navy blue), but that there is a curious uncertain ty as regards yellow—sonIC observers ranking this color very high. while others as decidedly prefer orange (yellowish red) and yellow green. ('21 The method of expression, on the other hand, seeks to reconstruct the affective consciousness from a study of its bodily symptoms or mani festations. It is a matter of common knowledge that men blush with shame and tremble with fear. The bodily indications of affection are, indeed, both widespread and easily observable, while at the same time they reflect the most subtle and delicate phases of affective process. Their common cause is to be found in changes of muscular innervation; the whole muscular system. voluntary and involuntary, answers to those changes of nervous excitation which cor respond, on the physical side, to elmnges in our state of feeling. We find, e.g., that the pulse becomes stronger during pleasant stimulation, and Weaker during unpleasant; the sphygmo graphic record shows that there is a change in the innervation of the heart. We find, in the same way, that breathing is deeper under a pleasurable, and shallower under an unpleasura ble, stimulus; the pneumographic record shows a change in the innervation of the respiratory muscles. We find that the volume of a limb or member—of the finger or arm—increases with pleasantness and decreases with unpleasantness; there is a change of innervation of the super ficial blood-vessels, and therefore of the amount of blood contained in them: the plethysinograph ic curve rises and falls as the stimulus varies. We find that muscular strength evinces a like fluetuation: our squeaze of the dynamometer is stronger when we are pleased than it is when we are displeased. And lastly, we have the same correlation of physical and mental in the case of involuntary movement. If the hand is laid upon the plate of a planehette while our mood is one of indifference, the pencil will make a little ragged spot upon the paper. but will take no definite direction. Let a pleasant stim ulus be given (a fragrant scent, a piece of good news), and the arm travels away from the body, as if the organism were reaching out after the pleasing object; the pencil traces a steady line outward. Let an unpleasant stimulus be given, and the arm conies in toward the trunk, as if the organism were withdrawing into itself, shrinking from the displeasing object; the pencil traces a steady line inward.
Why has not this method of expression, if it be so delicate as is here stated, settled once and for all the question of the number of affective qualities? There are three reasons. In the first place, the method is still very 'young, and the technical difficulties involved in the giving of stimuli, etc., have not yet been fully overcome. Secondly, the method presupposes that the subject of the experiment is, at the outset, in a normal, quiescent, indifferent state, and the regulation of this state is exceedingly difficult. And thirdly,
knowledge of the physiological meehanism of the curve variations is at present ineompleie: we have reason to believe that a particular feel ing must always be connected with a particular ehange of innervation, but we know also that 511(.11 a change may be wrought wholly within the physiological (and outside of the psycho logical) sphere. Hence. so long as introspection gives no decided verdict, the bodily symptoms may and will be differently interpreted. We said above that the pulse heats higher in pleas antness and more feebly in unpleasantness. A much more elaborate correlation has been sug gested by those who hold the alternative theory, of a large number of ultimate affections. To this pleaSallblOSS is indicated by strong and slow, unpleasantness by weak and rapid, heart beats; in excitement and depression, the pulse is simply strong and weak respectively: while strain manifests itself by weak and slow, relax ation by quick and strong. pulsations. We can not say that either side is right or wrong; we must suspend judgment until further evidence is submitted.
A third method, which has recently been pro posed, is (3) that of suggestive disintegration of the affective consciousness. If we assume that the concrete feeling is made up of three elementary affections, one from each of the three main directions, it should be possible (whether with or without recourse to the hypnotic state) to "suggest away" two of the components, and so allow the third to come to its full bodily expres sion. This method has not as yet received any extended trial.
It remains to consider the nature of the phys iological processes that underlie the appearance of an affection in consciousness. Sensations are conditioned directly upon the excitation of a determinate sense-organ. Affections, in all prob ability, are conditioned by excitatory processes which arise indirectly, by way of reaction, from these first processes. The secondary excitations may be supposed to originate within the cerebral cortex, though some psychologists have referred them to the medulla, or even to the sympathetic system; but whether they are localized (Wundt) or diffused (Meynert), we have no means of deciding. The English school have found a bio logical sanction for their traditional doctrine of pleasure-pain in the law that whatever is pleas urable tends to further and perfect life, and whatever is painful to disturb or destroy it. The law appears to be substantially true. Ex pressed in psychological terms. it would run somewhat as follows: A pleasant stimulus is a stimulus of moderate intensity, permitting the full exercise of attention, and connecting with the organic sensations set up by "anabolic" bodily processes; an unpleasant stimulus is one the intensity of which is adverse to maximal attention, and which connects with the organic sensations set up by "catabolic" bodily processes. Pleasantness and unpleasantness would then be conditioned, in the last resort, upon the intensity of stimulus: a result which accords well both with the results of experiment and with the notion of a diffused cortical reaction as sub strate of the affective process. On the other hand, as we have seen, later theory connects pleasantness and its opposite with the quality, excitement - depression with the intensity, and tension - relaxation with the duration of stim ulus. No one has yet attempted to work out these correlations upon the biological or teleolog ical side. Here, as before, we must look to the future for a settlement of the questions at issue.
Consult: for the theory of the three affective directions, W. Wnndt, Outlines of Psychology, translated by C. H. Judd (Leipzig, 1897) : for methods, 0. Kuelpe, Outlines of Psychology (London, 1895) ; E. B. Titchener, Experimental Psychology (New York, 1901) ; for the teleo logical law, H. Spencer, Principles of Psychology (New York, 1881), and Principles of Ethics (New York, 1892).