In Behn's romanticizing of Oroonoko's foreign beauty, she has made his visage and attitude heavily influenced by European norms. "His nose was rising and Roman instead of African," denying the inherent genetics of his culture; he also "loved, when he came from war, to see all the English gentlemen that traded" there and learned their language (14-15). The character's Westernization also includes pledges of monogamy to Imoinda "contrary to the custom of his country," "where men take to themselves as many [wives] as they can maintain" (17).
Behn's narrative is a window into the state of nature (mostly Locke's), in which men know no vice and lived with love (at least of their tribe)--and of course, of women. This distinction between relationships is a curious one, when applied to the theories of said state: neither Locke nor Hobbes made much room for women in their natural worlds. Relationships and childbearing are necessities regardless of a commonwealth's rule, and certainly women existed somewhere off to the side while the men were arguing over acorns. Locke allows the mother some authority where child rearing is concerned, but she is decidedly absent in concerns of property; a category into which wives arguably fall. Surely, in a Hobbsian war state, women will be vying for self-control and avoiding the men who wish to make them slaves (of a sort).
Where, then, do the women exist beneath the politics? The mother of any man's child is certainly important to him, and deserves protection by war or the distinction of property; but their XX chromosome, and the relationships which inherently lie in their biological functions, fall through the cracks of philosophical nature. Marriage cannot exist without the laws of matrimony defending it; and spoken vows only mean so much when each man must fight for himself. Is love, and, er, baby-making, also a free-for-all?