The issue of Intercom promotes an awareness of the world as a system that poses new possibilities and obligations for educators as well as policy makers. The first part includes interviews with and excerpts from the works of Denis Meadows, joint author of Limits to Growth; Mihajlo Mesarovic, co-author of Mankind at the Turning Point; Robert Heilbroner, author an An Inquiry into the Human Prospect; and Herman Kahn of the Hudson Institute. The second portion of this issue is addressed to the teacher. The teacher's dilemma--teaching about unsolved problems--is discussed. Five experimental lessons requiring five to seven class periods are offered as means for directing systematic thinking about world problems. These lessons include (1) a questionnaire to confront students with the possibilities and problems of the future, (2) an exercise using graphs to chart the choices available between linear and exponential growth, (3) a simulated city council decision on housing development translated into a problem of finite arable land resources, (4) the ethics of choices in coping with international food shortages, and (5) a simulation in which various interest groups make national policy recommendations with the assistance of computer projections. Teachers are urged to duplicate the contents of the journal for classroom use and to provide Intercom with feedback on the issue. (JH)