A prominent fallacious argument used against same-sex marriage is the good ‘ol ‘we’re only protecting our species’ one. I referred to it in a post a while ago:
[R]oughly, same-sex marriage is problematic because a) marriage is all about procreation and the raising of children and because b) evolution tell us that reproductive success is important, therefore: Gay marriage should be frowned upon.
I then went on to note the naturalistic fallacy committed by the proponents of this argument.
But there is a flip-side to this argument against same-sex relations from a supposedly evolutionary perspective. Might same-sex relations be evolutionarily advantageous? A affirmative answer to this question would not, of course, imply that same-sex relations were thereby to be understood as morally praiseworthy; that would be committing a naturalistic fallacy of its own. Rather, quite simply, it might show that contributions to evolutionary ‘success’–a poorly understood notion at best–can take many more forms than just the mere reproduction of offspring and thus defuse, in yet another fashion, the so-called ‘arguments from evolution against gay marriage.’
In reviewing Lisa Cohen‘s All We Know: Three Lives (a biography of Esther Murphy, Mercedes de Acosta, and Madge Garland), Terry Castle writes:
For same-sex desire [Cohen] implies, has as much to do with introspection as it does with carnality, and in the ‘inopportune ardour’ of her subjects she recognises the potential for a certain radical mental freedom. It makes sense: to embrace one’s sapphic feelings – to come out to oneself – is necessarily to rethink the world. For not only is one made at once to confront one’s apparently permanent alienation from the ‘normal’ or mainstream, one finds one has to adjudicate, in the most piercing and personal way, on a raft of ethical, religious and scientific questions. Are one’s desires felonious or unnatural, as most traditional belief systems (distressingly) continue to insist? Or are they something rather more benign – simply a ‘variant’ expression of human sexuality? If the latter is the case, couldn’t one view same-sex passion, in turn, as a perhaps useful evolutionary adaptation? As an age-old demographic reality, possibly hardwired into the souls of some, that actually enriches and diversifies human civilisation? [From ‘You Better Not Tell Me You Forgot‘, London Review of Books, 27 September 2012]
Castle reminds us that reproductive success in producing offspring might not be the only way to understand successful ‘evolutionary adaptations’. Perhaps members of the species can, through their ‘variant expressions of human sexuality’ contribute to the ‘success’ of their species in other ways? The ‘radical mental freedom’ of the same-sex members of our species might spark an efflorescence of activities–perhaps artistic, scientific, literary, cultural–that make possible its adaptive success in a variety of environments. (Think Tchaikovsky, Wilde, Woolf, Turing – the list goes on and on.) Indeed, these activities by: enriching our lives, making them worth living, enabling us to find meaning in this world, might even(!) facilitate the reproductive success of the species. (Some might think, of course, that the excessive devotion paid to Turing’s children–the modern electronic computer–does no such thing.) Viewed in this light, the presence of species members who do not partake in opposite-sex relations–with or without producing offspring–might come to appear as a positive characteristic of the species.