Importance of Ontogeny to Psychology--Development of the Child-Soul--Commencement of Existence of the Individual Soul--The Storing of the Soul--Mythology of the Origin of the Soul--Physiology of the Origin of the Soul--Elementary Processes in Conception--Coalescence of the Ovum and the Spermatozoon--Cell-Love--Heredity of the Soul from Parents and Ancestors--Its Physiological Nature as the Mechanics of the Protoplasm--Blending of Souls (Psychic Amphigony)--Reversion, Psychological Atavism--The Biogenetic Law in Psychology--Palingenetic Repetition and Cenogenetic Modification--Embryonic and Post-Embryonic Psychogeny
The human soul--whatever we may hold as to its nature--undergoes a continual development throughout the life of the individual. This ontogenetic fact is of fundamental importance in our monistic psychology, though the "professional" psychologists pay little or no attention to it. Since the embryology of the individual is, on Baer's principle--and in accordance with the universal belief of modern biologists--the "true torch-bearer for all research into the organic body," it will afford us a reliable light on the momentous problems of its psychic activity.
Although, however, this "embryology of the soul" is so important and interesting, it has hitherto met with the consideration it deserves only within a very narrow circle. Until recently teachers were almost the only ones to occupy themselves with a part of the problem; since their avocation compelled them to assist and supervise the formation of the psychic activity in the child, they were bound to take a theoretical interest, also, in the psychogenetic facts that came under their notice. However, these teachers, for the most part, both in recent and in earlier times, were dominated by the current dualistic psychology--in so far as they reflected at all; and they were totally ignorant of the important facts of comparative psychology, and unacquainted with the structure and function of the brain. Moreover, their observations only extended to children in their school-days, or in the years immediately preceding. The remarkable phenomena which the individual psychogeny of the child offers in its earliest years, and which are the joy and admiration of all thoughtful parents, were scarcely ever made the subject of serious scientific research. Wilhelm Preyer was the pioneer of this study in his interesting work on _The Mind of the Child_ (1881). To obtain a perfectly clear knowledge of the matter, however, we must go further back still; we must commence at the first appearance of the soul in the impregnated ovum.