The philosophy of personhood deniers

Peter Kreeft:

Thus the crucial issue is: Are there any human beings who are not persons? If so, killing them might be permissible, like killing warts. But who might these human non-persons be? Jews? Blacks? Slaves? Infidels? Counterrevolutionaries? Others have said so, and justified their genocide, lynching, slavery, jihad, or gulag. But pro-choicers never include these groups as non-persons. Many pro-choicers include severely retarded or handicapped humans, or very old and sick humans, as non-persons, but this is still morally shocking to most people, and many pro-choicers avoid that morally shocking position by including only fetuses as members of this newly invented class of human non-persons, or non-personal humans. I think no one ever conceived of this category before the abortion controversy. It looks very suspiciously like the category was invented to justify the killing, for its only members are the humans we happen to be now killing and want to keep killing and want to justify killing.