There is now some very general measure of agreement The needs of social reconstruction that if humanity is to escape the fate of having passed through the ordeal of world-wide war in vain, the recent era of destruction must be followed by a period of reconstruction and reorganisation, in which many of our systems, institutions, customs and beliefs must be tested, and where necessary refashioned, in the light of our changed ideals and points of view and of the widened experience of human needs and possibilities which our existence through these years of conflict has brought us.

The degree of success attained by any such attempt at Science and reconstruction readjustment on a large scale to changed standards and conditions, must to a very considerable extent depend upon the advance that is achieved by, and the application that is made of, the various branches of science dealing with the phenomena of human life in all its aspects. Biology, physiology, medicine, hygiene, economics, politics, law and education must all contribute their share to the solution of the great problem of reconstituting human society upon a satisfactory peace footing. Above all perhaps, it is to the science of the human mind that we should most naturally turn for enlightenment in dealing with many of the most important aspects of this problem.

Unfortunately it so happens that Psychology is among the The present status of Psychology youngest of the sciences; its state of development, in comparison with that of many other disciplines, is as yet in no wise commensurate with the relative importance for human welfare of the problems with which it is concerned. Conscious of this disproportion between our present knowledge and the weight of the matters that are at stake in any application of psychological theory to practical affairs, many leading psychologists have preferred to postpone any attempt at such application until the more important results of recent research, many of which are still matter for controversy, shall have been firmly established upon a wider and more unassailable foundation.

Perhaps as a consequence of this attitude (praiseworthy no doubt in itself), and of its effects—direct and indirect—upon psychological outlook and procedure, there exists at the present time a fairly widespread notion that Psychology is largely a matter of empty speculations or trivial technicalities, "a happy refuge for the lazy industry of pedants[2]," as a well known author has recently called it, with little or no bearing upon the larger problems of human life and conduct. It would appear, however, that the war—with its urgent call for immediate practical action—may have proved the means of inducing The application of Psychology to practical problems psychologists to adopt a less academic attitude in the pursuit of their science; of compelling them to carry out a stocktaking of the results already achieved with a view to ascertaining which, if any, are of a nature to throw light upon the actual problems of the time, and to work out in detail the application of psychological principles to these problems in all cases where such application promises to be of importance. Thus, immediately following upon the entrance of the United States into the war, the psychological resources of that country were mobilised by the American Psychological Association with a view to the immediate investigation of urgent questions affecting the conduct of the war. Under a central committee there were constituted no less than twelve subcommittees, each in charge of a special field and each acting under the chairmanship of a psychologist of special eminence in that field. Previous to this there had already been formed in this country a War Research Committee of the Psychological Subsection of the British Association to deal with problems of practical and theoretical importance connected with, or arising out of, the war. Assistance on a considerable scale in a variety of matters of direct military importance has also been rendered by several of the psychological laboratories attached to the Universities of the United Kingdom.

It is perhaps, however, more especially on the medical side that the question of the utilisation of psychological knowledge Medical Applications of Psychology for practical purposes has been brought into prominence by the war. The very large number of soldiers and civilians suffering from war-shock in its various forms has emphasised the need for psychological treatment of the functional nervous disorders; and has drawn further attention to the various methods of treatment by suggestion, re-education, psycho-analysis and other psycho-therapeutic measures, which even before the war were beginning to attract widespread interest. The work that had been done by these methods before the war had indicated that there existed a very considerable prevalence of nervous troubles even among those who were apparently subjected to no abnormally high degree of mental strain. The examination of many cases of war neuroses has shown that there is little if any qualitative difference between the case of those who break down under the abnormal pressure of war conditions and the War-shock case of those who are unable to stand even the relatively mild stresses and difficulties incidental to a time of peace. All persons are, it would appear, liable to suffer nervous breakdown if subjected to emotional strain beyond a certain limit; this limit varying, however, very considerably from one individual to another. Modern war increases to some degree the strain to be borne by almost everyone, the increase being very great in the case of those actually engaged in fighting; as a consequence the limit is passed, and some form of nervous disability or breakdown occurs in a large number of persons who would have remained unaffected during peace.

The amount of strain that can be actually borne with impunity by any individual is no doubt dependent upon a considerable Psychic integration number of complex conditions. Recent research has shown that among the psychological conditions one of quite special importance is constituted by the general state of integration of the motive forces of the mind. A person whose instincts and impulses are co-ordinated sufficiently to maintain, as regards all the leading aspects of life, a relatively harmonious functioning of the whole personality, can preserve mental health in circumstances under which a less integrated mind would fail, owing to the waste of energy occasioned by the internal struggles of the conflicting tendencies and emotions aroused in situations of difficulty or Importance of correct mental development danger. The attainment of the desirable degree of mental integration is itself very largely dependent upon a process of successful mental growth and development, in the course of which the conflicting tendencies and motives (of which the mind is so largely made up) so modify and mould each other as to permit of the proper discharge of psychical energy along all suitable channels without undue friction or inhibition. Great importance attaches, therefore, from the point of view of mental efficiency and stability in adult life, to the influences which control the development of the conative trends during childhood and adolescence.

It is to the consideration of one of the most potent of these Family influences influences that the present pages are devoted. Even on a superficial view it is fairly obvious that, under existing social conditions the psychological atmosphere of the home life with the complex emotions and sentiments aroused by, and dependent on, the various family relationships must exercise a very considerable effect on human character and development. Recent advances in the study of human conduct indicate that this effect is even greater than has been generally supposed: it would seem that, in adopting his attitude towards the members of his family circle, a child is at the same time determining to a large extent some of the principal aspects of his relations to his fellow men in general; and that an individual's outlook and point of view in dealing with many of the most important questions of human existence can be expressed in terms of the position he has taken up with regard to the problems and difficulties arising within the relatively narrow world of the family.

Besides showing the importance for mental development of their importance, difficulty, and complexity the problems connected with family life, modern psychological research has also revealed something of the nature of these problems. It is true that of the results obtained in this field there are as yet few, if any, which can be regarded as definitely settled; many, no doubt, will, in the light of future work, be seen to require more or less extensive revision, qualification or addition; some perhaps may have to be rejected altogether. Nevertheless it would appear that, as a consequence of the work already done, certain main principles at least have emerged so clearly as to justify, if not indeed to demand, the serious attention of all those who, at this critical period of human history, have to deal directly or indirectly with questions affecting family life in one or more of its numerous aspects. The sociologist, the moralist, the spiritual adviser, the teacher, the family physician and the parent are all intimately concerned with such questions; and it is primarily with the needs of such as these in view that the present brief exposition of the subject has been undertaken. After what has been already said, it is perhaps unnecessary to offer any further warning against accepting all the results of psychological investigation which are here set forth as claiming equal validity or as being equally capable of generalisation or application on a large scale. No dogmatic enunciation of facts or principles is here attempted or desired, even where, owing to the endeavour to avoid entering upon the discussion of matters too intricate or controversial to fall within the scope of our present treatment, the statements may possibly appear somewhat dogmatic in form. Our aim is rather to produce a more widespread realisation of the immense and far-reaching significance of the psychological problems connected with family life; to indicate some of the ways in which psychological knowledge has thrown light upon the solutions of these problems; and perhaps, by these means, to be of some assistance to that very large class of persons who, at one time or another during their lives, find themselves compelled to deal with such problems—whether as entering into their own lives, as affecting others for whom they are responsible, or as forming part of larger questions, social, religious, medical or pedagogic, in which they have an interest. To those who have once realised the complexity, the obscurity, and above all the tremendous intensity of the psychic factors entering into these problems, there can be little doubt that in so far as Psychology is able to afford some reasonably sure guidance as to their solution, it will have achieved one of the most successful and valuable of all applications of science to social and ethical phenomena. The time for such application on a large scale has not yet come. But the progress that has been already made would seem to indicate that the expectation of some very real assistance in these matters from the science of Psychology is no longer hopeless.