For Warren the central question in the debate over abortion is the status of the fetus as a moral person. According to Warren a fetus, while part of the human community in the genetic sense, is not a member of the moral community as it does not meet the personhood criteria, and therefore can be justifiably terminated. It’s important to note the difference between being a biological and moral member of a community. A fetus is biologically human but that doesn’t make it morally human, instead, as Warren presents, a list of criteria must be met to be considered a person and part of the moral community.
An interesting point is that Warren doesn’t say that being human, or of the species Homo sapiens, is a criterion to personhood. This leaves the opening for any other species that may one day meet these criteria to be morally considered as persons, such as chimps, dolphins, or even aliens.
Warren’s five criteria for personhood are consciousness, reasoning, self-motivated activity, capacity to communicate, and presence of self-concepts. While not a definition of what it is to be a person, it does list the central features of moral personhood. The first three particularly seem to encompass the base necessity of cognitive functions to be able to think in a moral fashion. Unfortunately a fetus cannot be said to exhibit any of the five criteria, with the exception of consciousness, and is therefore morally comparable to a chicken or a fish. This comparison is a problem for many who argue that the fetus is a person on account of it being human, but as we already noted that is not enough. "If the right to life of the fetus is to be based upon its resemblance to a person, then it cannot be said to have any more right to life than a newborn guppy... and a right of that magnitude could never override a woman's right to obtain an abortion at any stage of her pregnancy."
Still, many would argue that the fact that a human fetus has the potential for moral capacity, unlike a chicken or fish, is sufficient enough it to be considered a person. In response to this Warren asks us to imagine a scenario in which we have been requested to share our DNA with an alien species so that it might make clones of us. Even if the process created a thousand new lives, without any harm done, it would still be morally acceptable to terminate the procedure and in the process denying the existence of a thousand potential persons (clones). For Warren the interests...