474 



PSYCHOLOGY 



fibres. Again, all the experimental methods for 

 establishing the law assume the equality of least 

 sensible differences. Thus, if there be stimuli 

 measured respectively by 100, 101, 200, 2O2, causing 

 sensations x, x', y, y", such that z' is only just 

 distinguishable from x, y' only just distinguishable 

 from y, it is assumed that 3? - x = y- y, an 

 assumption which neglects the important fact 

 that there is no mental content corresponding 

 either to (x' - x) or to (j/ - y). Finally, even if 

 the law can be held to "be established, it is not 

 clear that it requires to be interpreted (with 

 Fechner) as properly psycho-physical. It may 

 also be held that the law is really physiological, 

 the intensity of the stimulus being modified in this 

 way by irradiation in the nerve-centres ; while 

 \Vundt has attempted a psychological interpreta- 

 tion of it, maintaining that it holds of the relation 

 bet ween mere sensation and the ' apperception ' 

 of the sensation by the direction of attention to it. 



Mental ' Faculties.' The observation and de- 

 scription of mental facts have led to a classification 

 of them, according to their degrees of likeness, into 

 certain orders ; and these have been frequently 

 spoken of as different powers or functions of the 

 mind. In the earliest stage of psychological in- 

 quiry we even have them described as different 

 parts of the soul. In this way Plato distinguishes 

 desire, anger, and reason, and locates them in the 

 lower part of the body, in the heart, and in the 

 brain respectively. But the classification which 

 had most influence upon subsequent writers was 

 Aristotle's. His distinction of thought and desire 

 is the origin of the dual classification of intellectual 

 and active powers (each with many subdivisions) 

 which was for long almost unanimously adopted. 

 A tripartite classification Cognition, Feeling, and 

 Desire or Will was put forward by the psycholo- 

 gists of Kant's time, accepted by Kant, and since 

 his time ( in Great Britain since Hamilton's time) 

 has been very generally adopted. The value of 

 such classifications is easily, and has often been, 

 overestimated. In the first place, it is clear that, 

 although such functions or faculties may be dis- 

 tinguished, they do not operate apart from one 

 another. No concrete state of mind consists merely 

 of knowledge or merely of will ; nor can it be pro- 

 perly called by one of these names, except as a 

 means of describing it by its most prominent char- 

 acteristic. In the second place, it lias to l>e borne 

 in mind that it is no explanation of a mental fact 

 to refer it to a mental faculty. To maintain, as 

 Kant, Hamilton, and Lotze did, that there are 

 certain fundamental conscious functions or con- 

 scious elements which cannot be reduced to so 



single function or element, gives no real snp|)ort 

 to the view which seems to underlie much of the 

 'faculty-psychology' the view that mind is a con- 

 geries of distinct faculties, and psychology a process 

 of labelling facts and putting each into its proper 

 compartment. To refer phenomena to memory, 

 generalisation, &c. as their causes is to mistake a 

 name for an explanation. 



The ' Faculty-psychology ' descrilied and demol- 

 ished by the Englisli Associationista and by Herbart 

 is, however, rattier a mode of thought into which 

 certain writers have frequently lapsed than a met hod 

 which they have consciously adopted and defended. 

 And the quest for a simple and uniform mental ele- 

 ment from which all the wealth of conscious life 

 has been derived is not therefore successful, because 

 the faculty-jwychology is unsuccessful. Herliart 

 regards the interaction of presentations as account- 

 ing for all mental phenomena; in a similar way H. 

 spencer seeks to derive mind from a succession of 

 somethings which can only lie described as analog- 

 ous to nervous shocks. But the difficulty of both 

 is to paw from this objective element to the feeling 



of pleasure or pain, aptly descriU-d by Hamilton as 

 subjectively subjective, or to the phenomena of 

 Volition. Accordingly, many psychologists who are 

 at one with llcrhait ami the Associationists in 

 rejecting the conception of faculties as a mode of 

 explaining facU yet hold that the final analysis 

 we can reach of consciousness or of mental pheno- 

 mena does not enable us to derive subjective feeling 

 (of pleasure or pain) from presentation, or activity 

 from either, the three elements being involved in 

 the simplest state of consciousness ( the term ' con- 

 sciousness,' as distinguished from 'self-conscious- 

 ness,' lieing here used as a quite general term for 

 any mental state). 



Attention. Many of the most important contro- 

 versies of psychology centre in the question of the 

 nature and extent of the activity involved in con- 

 sciousness. In its simplest form this activity is 

 seen in the subjective reaction involved in appre- 

 hending a presentation ; in its most developed form 

 it is the act of will which determines a course of 

 conduct upon which momentous issues are known 

 to hang. In the latter case, as well as in the 

 former, the critical point is the direction of Atten- 

 tion. Now attention is generally allowed not to 

 be a special ' faculty,' or separate' activity different 

 from the elements of consciousness already de- 

 scribed. It is simply consciousness regarded as 

 active and as concentrated on some portion of its 

 objective content, whereby the intensity of that 

 portion is increased. The point in dispute is 

 chiefly whether this active concentration is ulti- 

 mately determined by the strength of external 

 factors. It is clear that the direction of attention 

 is conditioned by the previous mental groupings 

 of ideas. Further, attention involves a mus- 

 cular adjustment at any rate when directed to 

 objects of sense, and also (although in a less 

 marked degree) when directed to a train of thought. 

 These facts are differently interpreted. On the one 

 hand, Bain, Kibot, and others find the basis of 

 attention in the muscular adjustment ; on the 

 other hand, the muscular adjustment is looked 

 upon as the organic expression and development 

 of subjective activity ; and this subjective activity 

 is held to lie involved in the simplest state of con 

 sciousness. The one view looks upon the external 

 as determining and even somehow producing the 

 internal. According to the other view the [process 

 is one in which a subjective or spiritual factor 

 expresses itself through and gradually extends iU 

 control over an organic and physical environment. 



Setutation. Sensations are commonly defined as 

 the simple mental states which result from nervous 

 stimuli. This physiological reference enables us to 

 distinguish the Special Senses, with their clearly 

 defined organs adapted to the reception of different 

 kinds of external stimuli, from Organic or CJeneral 

 Sensibility, which arises from the state of the 

 internal organs of the body (such as the alimen- 

 tary canal, the lungs, and tiie heart), and from the 

 Motor Sensations. These last (which play so im 

 1 1' >i i ant a part in the development of knowledge) 

 are due to the central excitation of a motor or 

 efferent nerve, and the consequent contraction of 

 the muscle in which it terminates (see MusCLK, 

 NHIVOUS SYSTEM). The sensation both modi- 

 fies and is modified by the conscious state into 



which it enters. We have i xpeiience, and 



can form no valid conception, of the mere sensa- 

 tion. For the subject which experiences it, it is 

 merely an element in a complex and ever-changing 

 whole. This is a |x>int which has been commonly 

 overlooked by the Associations! psychologists. 

 They started with a succession of disconnected 

 mental molecules, .-ailed sensations, and attempted 

 to trace the growth of mental life from their com- 

 bination. But this i- to begin with an abstraction. 



