Originally given as a popular lecture course, this little book does not pretend to be a contribution to the formidable array of psychological literature. It is intended for those who have neither the time nor the training necessary to assimilate the standard works on the subject, but who want to know its elements; and to understand the principles on which our characters are formed and the means by which the process of thought is carried on, not so much from the scholastic point of view, as in relation to the problems of everyday life. It is hoped that many will find herein the key to things that have puzzled them in their own natures, for only those who hold such unsolved problems in their hearts can know how crippling and tormenting they are. This book does not aim so much at an orderly setting forth of the elements of psychology as at planting certain fundamental concepts in untrained minds so that they may serve as a basis for future studies. To this end the writer has adopted a pictorial, almost diagrammatic method of presentation in order that a framework of general ideas may be formed into which details may subsequently be fitted, having found this to be the best way to convey novel concepts to minds untrained in metaphysical subtleties. The teachings of no special school of psychology are adhered to; the writer is indebted to all, but loyal to none, holding that in the absence of any accepted standard of authority in psychological science each student must review the doctrines offered for his adherence in the light of his own experience. This book is essentially practical in aim, written in response to a practical need. In her experience of remedial psychology, the writer saw that many cases of mental and nervous trouble would never have developed if their victims had had an elementary knowledge of the workings of the mind; she also found that many patients required nothing but an explanation of these principles to put them on the road to recovery, and that even when more than this was needed to effect a cure, such a knowledge greatly expedited the treatment by enabling the patient to co-operate intelligently. So far as she is aware, there is no book that deals with psychopathology, not from the point of view of the student, but from that of the patient who needs an elementary knowledge of the laws of the mind in order to enable him to think hygienically. This book is written to fulfil that need; it is not only applicable, however, to those who are sick in mind or estate, but to those also who desire to develop their latent capacities by means of the practical application of the laws of thought and character. The Machinery of the Mind CHAPTER I THE PHYSICAL VEHICLE OF CONSCIOUSNESS In order to arrive at an adequate understanding of mental processes it is necessary to have some idea of the machinery whereby the mind makes contact with the body.