=The General Field.= Psychology has now reached that stage in its development where it can be of use to humanity. It can be of use in those fields which demand a knowledge of human nature. As indicated in the first chapter, these fields are education, medicine, law, business, and industry. We may add another which has been called "culture." We cannot say that psychology is able yet to be of very great service except to education, law, and medicine. It has been of less service to the field of business and industry, but in the future, its contribution here will be as great as in the other fields. While the service of psychology in the various fields is not yet great, what it will eventually be able to do is very clear. It is the purpose of this chapter to indicate briefly, the nature and possibilities of this psychological service. =Education.= Throughout the preceding chapters, we have emphasized the educational importance of the facts discussed. There is little left to say here except to summarize the main facts. Since education is a matter of making a child over into what he ought to be, the science of education demands a knowledge of the original nature of children. This means that one must know the nature of instincts, their relations to one another, their order of development, and the possibilities of their being changed, modified, developed, suppressed. It means that one must know the nature of the child's mind in all its various functions, the development and significance of these functions,--memory, association, imagination, and attention. The science especially demands that we understand the principles of habit-formation, the laws of economical learning, and the laws of memory. This psychological knowledge must form the ground-work in the education of teachers for their profession. In addition to this general preparation of the teacher, psychology will render the schools a great service through the psycho-clinicist, who will be a psychological expert working under the superintendents of our school systems. His duty will be to supervise the work of mental testing, the work of diagnosis for feeble-mindedness and selection of the subnormal children, the teaching of such children. He will give advice in all cases which demand expert psychological knowledge.