The purpose of this note is to examine Daniel Callahan's "What Obligations Do We Have to Future Generations?". He supplements and criticizes Martin P. Golding's article, "Obligations to Future Generations". He argues mainly following points: (1)Our obligations to the future stem from our obligations to the past; (2)Moral dilemmas can arise across the generations, where the discharging of our obligations to the living could require acting in ways which would have harmful consequences for future generations; (3)A surplus-exercise comes into being at just that point when we discover that the way we exercise our rights jeopardizes the rights which future generation will claim, i.e., those fundamental rights we now claim.