Gay people should marry.

I like to take advantage of people's laziness. I agree to Con's R1 terms (i.e., to the lack of terms).I understand "should" in the morally-significant sense to imply an obligation to some particular action. To say that "X should do Y", in other words, entails that X is morally obligated to do Y. Hence, to negate the proposition that "Gay people should marry", it is incumbent upon me to demonstrate that no such obligation exists, or, at the very least, to instill in voters sufficient doubt that such obligation exists.Moreover, I distinguish this debate from debates about the ethical or legal permissibility of gay marriage (i.e., debates about whether homosexuals ought to be allowed to marry) because of the explicit formulation of the topic as "gay people should marry", which indicates obligatory activity within the realm of permissibility. Hence, even if I were not to take advantage of Pro's laziness, the semantic footwork required to escape from the wording of the topic would be rather impressive.Normative ContingencyThe Normative Contingency Thesis (NCT) argues that normative statements are necessarily grounded on some fundamental value, and that each proposition in a deductive chain is therefore contingent on one or more propositions preceding it. "We ought to help the poor", for instance, might ultimately presuppose something like "human life is valuable" as its first-level value premise. NCT, however, recursively applies contingency to the fundamental value underlying the entire chain, demonstrating that this fundamental proposition is itself contingent on the discursive fiat of those individuals who are advancing some moral theory or other set of propositions. As such, you can observe two systems of perfect deduction which nevertheless reach wildly different conclusions precisely because of the different first-level claims each makes. If I take "God exists" as axiomatic, for example, I can derive an elegant set of conclusions; yet, I can also do the same if I take the converse as an axiom. This reveals the status of fundamental moral propositions (e.g. "human life is valuable") as essentially arbitrary, and therefore, as objectively non-binding. In other words: the problem of normative contingency entails the nonexistence of objective moral factsUniversal BindingnessWhen making general moral claims about a particular demographic, e.g., homosexuals, one criterion for legitimate normative claims is that the proposition ought to be applicable to all members of the referent demographic. If I say "Black people ought to be able to vote", I certainly don't mean "All black people except those living in Nebraska". I mean all of them. Similarly, for Pro's claim to have normative weight, we must be able to attribute to it the property of universal bindingness, according to which the proposition can be said to apply to everyone. Upon cursory examination, the burden is on Pro to demonstrate a non-contingent obligation to marry (for homosexuals specifically, though proving a more general obligation for anyone to marry is also sufficient, although unnecessary). If [I prove that] he fails to do so, you default Con.Even according to some of the traditional metrics, like happiness or utility, this obligation is not obvious. There is no prospective way of demonstrating that marriage would be guaranteed to maximize the positive value derived from a homosexual couple's relationship. Even if all homosexual couples desired marriage, there is little way to discern the long-term net gain or loss. After the honeymoon phase of the marriage ends, and we turn the clock forward 5 or 10 years, it is impossible to tell where the couples will all be, much less whether they will still be blissfully united. At face value, then, it already appears that such an obligation [to marry] is ungrounded.Moreover, though: to whatever extent heterosexual marriage is representative of homosexual marriage, the prevalence of divorce and unmarried cohabitation suggests that the value of marriage is not as substantial as an early estimate might suggest. Marriage is an old institution, and acceptance of so-called "alternative lifestyles" has begun to delimit a space in which people are free to invent themselves outside the usual outlets of self-actualization. Many couples may not want to marry; others may want to engage in open polyamory; others may marry, but end up in bitter divorce proceedings. The sheer quantity of possibilities for the future of any relationship--including homosexual relationships--suggests rather heavily that there is no moral obligation to participate in this particular institution. Otherwise stated: there is no reason to believe that homosexuals are morally obligated to marry.So, I think Pro's work is cut out for him: on the one hand, NCT demonstrates that there is no non-contingent first principle which can be used to ground a general moral obligation [for homosexuals] to marry. On the other hand, even examination under a common metric--happiness/utility--proves our inability to promise homogeneous outcomes to an entire demographic, which diminishes the credibility of potential normative arguments. Still, I think Pro will have a lot of fun maneuvering in the coming rounds to produce a challenging argument. My hat is off to him in this task.