Philosophy Of

Peter Singer 

Singer argues that newborns lack the essential characteristics of personhood—"rationality, autonomy, and self-consciousness"—and therefore "killing a newborn baby is never equivalent to killing a person, that is, a being who wants to go on living."
Singer agrees and believes the notion of the sanctity of life ought to be discarded as outdated, unscientific and irrelevant to understanding problems in contemporary bioethics.

http://en.wikipedia.org/wiki/Peter_Singer