The most striking biological change that comes to the boy on his way to manhood is that of puberty. The church and the state have attested the vast importance of this experience for political and religious ends by their ceremonials of induction into the responsibilities of citizenship and the obligations of formal religion. Among the least civilized peoples these ceremonies were often cruel, superstitious, and long drawn out in their exaction of self-control, sacrifice, and subordination to the tribal will. The sagacity of the elders of the tribe in preserving their own control and in perpetuating totemic lore must compel the unfeigned admiration of the modern ethnologist. The Athenians with their magnificent civilization exalted citizenship and the service of the state far beyond any modern attainment. The way of the youth today is tame, empty, and selfish as compared with the Spartan road to manhood and the Roman ceremonies attendant upon the assumption of the _toga virilis_. As a rule modern churches have too lightly regarded the profound significance of ancient confirmation services--Jewish, Greek, and Catholic. Knowledge of what transpires in the body and mind of adolescence proves the wisdom of the ancients and at the same time attracts both the educator and the evangelist to study and use the crises of this fertile and plastic period. The process of transformation from childhood into manhood begins in the twelfth or thirteenth year, passes its most acute stage at about fifteen, and may not complete itself until the twenty-fifth year. It is preceded by a period of mobilization of vitality as if nature were preparing for this wonderful re-birth whereby the individualistic boy becomes the socialized progenitor of his kind. The normal physiological changes, quite apart from their psychological accompaniments, are such as to elicit the sympathy of intelligent adults. Early in pubescent growth the heart increases by leaps and bounds, often doubling its size in the course of two years or even one year. There is a rise of about one degree in the temperature of the blood and the blood pressure is increased in all parts of the body. The entire body is unduly sensitized, and the boy is besieged by an army of new and vivid sense impressions that overstimulate, confuse, and baffle him. He is under stress and like all persons under tension he reacts extremely and hence inconsistently in different directions. He cannot correlate and organize his experiences. They are too vivid, varied, and rapid for that. This over-intensity begets in turn excessive languor and he cannot hold himself in _via media_.