What are embryonic stem cells, why are they so exciting and yet controversial, and what can be done to move our society beyond the current moral and political impasse? To provide answers to these questions, we will begin with a basic introduction to the science behind stem cell research. We will then move to a description of the emerging field of regenerative medicine, the main reason why stem cell research has generated so much excitement in the scientific community. As we will see, the drive to develop stem cells for regenerative medicine has linked stem cell research with the controversy surrounding cloning technology. Finally, we will turn to the moral questions raised by human embryonic stem cell research: the immorality of both destructive human embryo research and human cloning, and the moral alternatives available to us as a society, which will allow us to realize the great medical promise of stem cells in a manner that respects the dignity of the human person.