  Anthropocentric views raise difficult questions about how much human material an individual needs in order to be a human being. Since normal human embryos are both human and organisms, they are human beings, albeit ones at the earliest stages of development (Feinberg 1980, 288–291). But when faced with an organism that has some human cells and some non-human cells, how is one to decide whether the organism is human, and hence, whether it is a human being? It is overly narrow to focus on transplants that affect neural tissue, since it is not plausible to suppose that an individual must have a human brain to be a human being: an anencephalic infant is a human being and would possess human moral status on an anthropocentric view. Presumably, replacing the entire inner cell mass of an animal blastocyst with hESCs would suffice to make the resulting individual a human being since, in normal human development, the inner cell mass is what goes on to form the fetus. In such cases, one could, at least in principle, end up with a human being surrounded by a non-human trophectoderm (the layer of cells surrounding the embryo which goes on to form the placental structures). If an anthropocentric view of moral status is correct then the Moral Status Framework would clearly condemn such research. On the other hand, having only a few non-human cells in the final individual would not suffice since a human with a porcine heart valve is still a human being. But where to draw the line is unclear, similar to the situation with objects that have vague identity conditions (Parfit 1984, 231–243; Thomson 1987; Thomson 1997; Piotrowska 2014).