The Moral Status of Human-Animal Chimeras with Human Brain Cells.

While there is not unanimity (across time or cultures), almost all who read this commentary will think that both they and a toddler have a moral status higher than that of a rat. For instance, they will think that a third party who has to choose whom to save from death should choose them over the rat, and the toddler over the rat. But what is it about humans that gives us this greater moral status? This question is particularly pressing when considering that scientists have begun creating human-animal chimeras with brains composed partly or wholly of human cells.