Opponents of human embryonic stem cell (hESC) research claim that such research is incompatible with the moral principle that it is always wrong intentionally to end a human life. In this essay, I discuss how that principle might be revised so that it is subject to as few difficulties as possible. I then argue that even the most defensible version of the principle is compatible with the moral permissibility of hESC research.

In the contemporary debate on moral status, it is not uncommon to find philosophers who embrace the the Principle of Full Moral Status, according to which the degree to which an entity E possesses moral status is proportional to the degree to which E possesses morally relevant properties until a threshold degree of morally relevant properties possession is reached, whereupon the degree to which E possesses morally relevant properties may continue to increase, but the degree to which E possesses moral (...) status remains the same. One philosopher who has contributed significantly to the contemporary debate on moral status and embraces the Principle of Full Moral Status is Mary Anne Warren. Warren holds not only that it is possible for some entities to possess full moral status, but that some entities actually do, e.g., normal adult human beings. I argue that two of Warren’s primary arguments for the Principle of Full Moral Status—the Argument from Pragmatism and the Argument from Explanatory Power—are significantly flawed. (shrink)

The author argues that individuality does not require indivisibility and that twinning can be explained as the reprogramming of blastomeres that already have begun to differentiate in accordance with the needs of the unified organism that originates at conception.

In a recent article published in the Journal of Law, Medicine & Ethics, David DeGrazia criticized the two pivotal assumptions that underlie President Bush’s policy on funding stem cell research. Those assumptions are that we originate as single-cell zygotes at the time of conception and that we have full moral status as soon as we originate.In this paper, I would like to concentrate on the first of those assumptions and show in light of recent findings in embryological development that DeGrazia’s (...) criticisms have to be rejected. I shall save my discussion of DeGrazia’s critique of the second assumption for a later article that can take into account DeGrazia’s further elaboration of his position. (shrink)

This essay deals with the question of the morality of abortion and infanticide. The fundamental ethical objection traditionally advanced against these practices rests on the contention that human fetuses and infants have a right to life, and it is this claim that is the primary focus of attention here. Consequently, the basic question to be discussed is what properties a thing must possess in order to have a serious right to life. The approach involves defending, then, a basic principle specifying (...) a condition living things must satisfy to have a serious right to life, and the answer given makes it unlikely that this condition is satisfied by human fetuses and infants, though this tentative conclusion could be altered by future scientific studies of the development of the human brain. As things stand at the moment, however, it seems unlikely that developing humans acquire the physical basis of the psychological capacities on which the right to continued existence rests, and therefore unless there are other substantial objections to abortion and infanticide that undercut the above line of thought, the conclusion is that such practices are not intrinsically wrong. (shrink)