Guidance for career development must be concerned not so much with helping young people learn how to earn a living as with learning how to live a life. In the early part of this century, certain conditions and attitudes prevailed which influenced the character of the career guidance profession. However, these conditions and attitudes are no longer applicable to the present and emerging periods. The profession is changing in response to the changed social context in which we function. As in the field of medicine, the trend in guidance is toward a greater emphasis on understanding the total developmental process of young people. The study and manipulation of environments are increasingly viewed as crucial vehicles for the achievement of guidance objectives. This concern with environmental encounters in both medicine and guidance, and a reconsideration of the nature-nurture controversy, should lead to greater attention being given to the interaction between intrinsic and extrinsic factors involved in the development of human behavior. The early individual psychological model now being challenged by the developmental-ecological model as a more appropriate frame for the conceptualization and implementation of guidance functions has implications for the present and for the future. (Author/EB)