KIE: Hanser examines Derek Parfit's contention in his treatise on rationalism, Reasons and Persons (Oxford University Press; 1984) that acts that are not reproductive in nature can nonetheless predictably affect the identities of future people, and that this fact has unexpected and important consequences for ethical theory. Hanser argues tht this fact is not as significant as Parfit believes it to be. The arguments of both scholars concern the morality of choices that, while causing future persons to be badly off, do not make them worse off than they would have been if the choices had not been made. Hanser concludes his essay with a discussion of responsibility for acts that will affect the health of future offspring.