Worries about the commodification of the body—from patenting human genes to buying human eggs to selling human organs—cut across the typical conservative-liberal divides in America. Some conservatives fear that human dignity is compromised by selling body parts; others believe that human liberty is undermined by restricting mutually beneficial transactions of the body. Likewise, many liberals believe that such buying and selling exploits women and the poor, while others defend the right to sell one’s body parts in the name of liberal autonomy. In the past few editions of The New Atlantis, essays by Eric Cohen (“Biotechnology and the Spirit of Capitalism,” Spring 2006) and Gilbert Meilaender (“Gifts of the Body,” Summer 2006) have considered these issues—first in general, then in the specific context of recent calls to permit an organ market in the United States in order to ameliorate the suffering of those waiting, perhaps in vain, for a transplant. To keep the conversation going, we asked Benjamin Hippen, a nephrologist, and Peter Lawler, a political theorist, to use the Cohen and Meilaender essays as the occasion to think about organ markets and the new commerce of the body.