In the natural world the reproductive process is not an end in itself but is at the service of a contingent history of evolutionary survival. If a particular species were to complete its own sexual relation then it would fall into a survival dead-end and could be wiped out by a change of environmental conditions, such as a new predator or parasite. Fitness can't be directly signaled because what is the most fit under all possible conditions can't be determined beforehand. Sexual signalling must therefore never be a perfect correspondence, never actually express a final state of things. It is in this sense that the peacock's tail could be seen as a symptom of the absence of a sexual relation in these birds. The females evolve to choose spectacular plumage as the males evolve to display it, so that it seems as though the aesthetic imperative of the plumage were employing the imperfectly matched preferences of both sexes for its own ends. In this sense the Lacanian axiom that there is no sexual relationship would simply be a restatement of the role of sexual selection in Darwinian evolution. This axiom is however posterior to another axiom which is perhaps more exclusively human, namely the non-existence of a relationship to death. And this non-relationship produces its own even more spectacular symptomatology, its own metaphysical peacock tails.