All friendship, all society, indeed all of human existence, arises from the physical difference of male and female human beings. From this physical difference arises the ground and purpose of human life, because it is the ground and purpose of nature. …The distinction between a man and a woman is a distinction as fundamental as any in nature, because it is the very distinction by which nature itself is constituted. It is the ability of two members of the same species to generate a third, that confirms them as members of the same species. It thereby confirms male and female members of the human species in that equality of rights to which they are entitled as members of that species.