is more and more coming to be realized that a thorough understanding of the aptitudes which the individual brings to his work is as important as the knowledge of the opportunities which the environment affords. In the remainder of this book we shall be concerned with the various systematic efforts that have been made or are now being made to study the individual himself, and to judge from a determination of his mental characteristics the type of vocational activity which he is best fitted to undertake with success. CHAPTER II THE SEARCH FOR PHRENOLOGICAL AND PHYSIOGNOMIC PRINCIPLES THE RISE OF EXPERIMENTAL SCIENCE The primitive magic, directed toward the formation of individual character, was displaced by the personal clairvoyance which attempted to diagnose the individual's mental and moral constitution on the basis of his own early acts, expressions, and physical characteristics. This soon gave way to a tendency to abandon, for the most part, such signs as did not relate in some actual or fancied way, to the individual's brain. This limitation of the field of significant signs may be related to the widespread interest in human physiology, historically associated with the knowledge of anatomy. The invention of the microscope, Harvey's proof of the circulation of the blood, the discussion centering about the automaton theory of Descartes, and the rapid development of surgical technique, brought about a most interesting spread of curiosity concerning the nature and mechanism of the human body. Balls and tournaments gave way to dissections and demonstrations as means of courtly entertainment. Celebrated surgeons exhibited their skill and knowledge, and lectured on the facts of physiology and anatomy in the formal presence of royalty and society. Court painters executed pictures such as "The Anatomy Lesson," some of them now cherished as famous masterpieces. Especially keen became the interest in the skull and brain in which, as Descartes taught, might be found the seat of the soul. Among the earliest of the rough discoveries was that concerned with the localization of special sensory and motor functions of the organism in particular regions of the brain. It was observed that irritation of certain parts of the surface or "cortex" of the brain, in cases where a portion of the skull had been removed, was followed by movement of particular parts of the body, and that individuals who had suffered from injury to certain parts of the brain seemed, on recovery, to be quite their usual selves, except that certain special capacities, as for instance the function of speech, were interfered with or quite destroyed. The unitary soul, described by Descartes as probably having its seat in the pineal gland, now bade fair to disintegrate into various minor faculties, each with its separate brain mechanism and its particular abode in some region of the skull.