Outlines of psychology / by James Sully.

  • Sully, James, 1842-1923.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of psychology / by James Sully. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    481/520 (page 457)
    dently said that our psychological analysis, aided by the physiology of the nervous system, enables us to some extent to solve the problem. Thus we have seen that all intellectual ability is in general determined by the perfection of the senses together with the closely conjoined intellectual function known as discrimina- tion. Fineness, or delicacy of discriminative sensibility, is thus one fundamental element of intellectuality. Further, we have learnt that power of attention, as illustrated in prolonged fixation, rapid transition from object to object and grasp or comprehensive- ness, assimilation or readiness in detecting similarities, as also re- tentiveness and associative power, are fundamental constituents of intelligence. In the case of feeling, again, we have traced down all emotional susceptibility to certain organically determined sensi- bilities to pleasure and pain ; and similarly we have found in active impulse under its double form, attention and (psychical) move- ment, the fundamental element in conation. If now we turn to the second condition of the problem and ask how far these elementary psychical capacities are measurable, we are confronted with certain obvious difficulties. Our psychical states are not quantitatively comparable in the way in which material magnitudes are so. We cannot, for example, say that one sensa- tion has precisely three times the intensity of another. Yet, as we have seen, the new science of psycho-physics, or, to use a more exact expression, psychometry, has made a promising beginning in carrying out certain simple quantitative determina- tions. Psychical phenomena may be said to exhibit three aspects under which they admit of quantitative comparison or measure- ment, (a) Of these the first and most obvious is Intensity. The various modes of determining this, in the case of the simpler psychical phenomena, sensations, have been dealt with above. It is evident that these methods of measurement are fitted to deter- mine individual variations. Thus individuals can be compared with some exactness in respect both of absolute and discriminative sensibility to intensity of light, sound, and so forth. It is probable that by help of a suitable psycho-physical apparatus other psychical