From time immemorial it has been an empirical fact of lay and clinical observation that constitutional endowment is a definite factor in predisposition to poor mental health. Prior to what one might characterize as the mental hygiene movement, the negative aspects of this fact were alone emphasized. Progeny of psychotic patients or nervously unstable persons waited for the inevitable. The advancement of chemistry, bacteriology and endocrinology carried the hope that the determinants of transmission would be revealed. With the blasting of this illusion (except in the minds of some of the faithful, who still look for deliverance at the hands of biochemistry), the messianic hope formulated itself in a psychotherapeutic approach. This started with the modest goal of urging that the personality aspects of growth and development should be considered of equal importance with the intellectual and the biologic set-up. From this the trend has developed to a belief that