The biological reasons for disallowing degrees of consanguine marriage are weak, since we can now tell, in most cases, if there is a danger of the parties carrying recessive genes and breeding genetically penalized infants, and also since, if that were a consideration, sterilization could ensure they never have natural children. And yet no one argues that cousins be allowed to marry, much less siblings. Why? There must be some who would want to, but we shrink back, because family relations would be harmed by constant worry about sexual experimentation, especially when there is an age difference, and therefore a particular danger of exploitation. In other words, the taboo helps to solidify family relations and provide a "safety zone" where conflicts over sexuality are less likely to arise.
Gay marriage seeks to rid us of the notion that heterosexuality is normal, otherwise, civil union would satisfy the complaints of gay couples. Heterosexual marriage is primarily, though not exclusively, formed for the sake of establishing families, not for easing the situation of couples. Heterosexuals do not want to undermine this aspect of marriage any further. They do not want to normalize "barren marriage", and while they may be prepared to say that homosexual adoption is better than institutionalization, they are not prepared to give up a preference for a father and mother. In other words, they want to express their preference for family formation, and the value of both father and mother. |
