SECTION J.— PSYCHOLOGY. 



MENTAL UNITY 

 AND MENTAL DISSOCIATION. 



ADDRESS BY 



WILLIAM BROWN, M.D., D.Sc, M.R.C.P., 



PRESIDENT OF THE SECTION. 



It is important to realise that the problem of mental unity and dissociation 

 is in direct relationship to the problem of unity and dissociation in the 

 physical and physiological spheres. The point of view from which we 

 should first approach it is that of biology. The general tendency 

 throughout evolution seems to be towards the building up of totalities or 

 wholes, in which each separate activity takes place in relation to the 

 whole. The general conception is not that of a purely mechanistic 

 scheme in which we begin with particles of matter and consider how they 

 interact with one another to produce a more and more complex system, 

 but one in which there is a guiding unity from the beginning. We may 

 indeed, as metaphysicians, assume that there is a guiding unity of the 

 entire universe. But short of such an ultimate generalisation we find 

 that observation itself reveals this tendency towards a progressive 

 development and multiplication of unities, in relation to which individual 

 activities occur. 



In one sense, biology may be regarded as the most fundamental of 

 the sciences, and even the simpler physical and chemical activities occur 

 as parts of systems, which may be likened to organisms in having an 

 environment to which their reactions are adjusted. This biological point 

 of view needs for its completion the psychological point of view, which is 

 not something distinct from the biological, but a continuation of it- 

 Psychology is a completion of biology as a science, and gives further 

 meaning to it. The unity of the organism becomes more intelligible 

 when we think of it as a mental, and in part a conscious, unity. It is a 

 unity in plurality. Physically, the organism is a unity of parts in spatial 

 relation to one another ; psychologically, it is a system of mental ten- 

 dencies in relation to one another. What we find physically is a reaction 

 to an environment in the form of reflex action, simple or conditioned. 

 Psychologically, response to external stimulation is the satisfaction of 

 conation, and, at higher levels, satisfaction of desire, &c. Biologically, 

 it is the struggle for existence, with all that this involves. Psychologically, 

 it is a conscious striving first of all for something that the individual 

 does not know— towards a goal which he gradually realises, gradually 

 learns to understand as he achieves it or fails to achieve it. However 

 helpful the biological concepts of tropisms and conditioned reflexes may 

 be as explanatory factors, the psychological point of view throws further 



