Responsibility to future generations appears at first to be an uncomplicated concept, and its widespread appearance in public pronouncements and political rhetoric testifies to its apparently widespread endorsement by public opinion. Moreover, advances in science and technology have directly increased the urgency and relevance of this concept as the present generation becomes ever more aware of its capacity to impact (with industrial chemicals, environmental exploitation, and climate change), destroy (with nuclear and biological weapons), and alter (with genetic engineering) the life conditions of the generations that will follow.

However clear and urgent the concept of responsibility to the future might seem upon casual reflection, as philosophers examine that concept with their typical meticulous analytic scrutiny, numerous puzzles, paradoxes, and quandaries emerge. Questions concerning the ontological, epistemological, and moral status of future persons (stipulated here as having non-concurrent lives with the current generation) are crucial. Most fundamentally...