I am not sure that there is any way to objectively determine whether there is, or ever could be, enough to go around. Obviously, human needs are elastic. If"enough" means a car for every adult or family, an air-conditioned home and a pesticide-rich lawn, then the answer is clearly "no." If"good" medical care includes a right to kidney dialysis and by-pass surgery, then again, we may never all have enough. At the same time though, the human capacity for meeting needs is endlessly expansive and inventive. New forms of energy, combined with the powerful drive toward miniaturization (and hence less need for energy to accomplish many kinds of tasks), could make some of the more pessimistic estimates obsolete.