What philosophical branches do sex and marriage each belong? In one context, sex is metaphysical. It is part of your eternal identity. Your vote doesn't change your genetics. In this context sex (metaphysical) has primacy over marriage. In another context, sex is Ethical/Political…An interaction between two people. Marriage is a also Political Convention, upon which all Family Law is based (custody, child support, divorce,
etc.) In this context marriage has primacy over sex.