The Greeks and Romans often exposed their babies, especially if the child was of the wrong gender, malformed or from the wrong father–or, more simply, when a child was not needed. It was lawful, but Jewish and then Christian teachers did everything to prevent the practice among their own groups. Most of the arguments used by Christians were borrowed from their Jewish predecessors. The unique value of every human being and God's commandments were emphasized in both religions. Above all, they...