Property and authority were passed on only to sons and daughters begotten in marriage. Legitimacy provided for order in society. Sex outside of marriage and illegitimacy continue to tear families and marriages apart. They are the source of grave social problems. The current debate over our national welfare system and other social problems is evidence of that.
Most penalties are for committing the sexual acts themselves.
The cleric who fathers a child, however, has all the responsibilities toward the child that any father has. By natural and moral law he must provide for the child. My son is about to marry a Jewish girl. In the beginning, they planned to have both a priest and a rabbi at the services. His fiancee and family have made all their arrangements, but my son has done nothing about the priest and it appears that it will be a totally Jewish ceremony.