The Supreme Court case Obergefell v. Hodges from 2015 which granted same sex couples the right to marriage is one that can be argued for very successfully from both a stance of accepting/encouraging individuality and from a stance of utilitarianism. To begin, I want to turn your attention to the idea of individuality. As I said in the third chapter of my book On Liberty, “it is essential that different people be allowed to live different lives.” Put another way, so long as your own version of living out your life does not infringe on others’ rights of happiness, there is no reason to hinder your ability to live however you would like. This idea shines through in ideas such as freedom of religion and freedom of speech as well. Being able to practice whichever religion you like allows for more diversity in a community which can maintain the small truths in all religions until a more full truth can be discovered through the combination of them all. Similarly, being able to lead whatever type of lifestyle you find most comfortable (whether it be in a heterosexual, homosexual, asexual, or otherwise relationship) allows for a community to remain diverse and keep rigorous debate up which may lead to a better understanding of the truth or relationships which can lead to greater happiness of the society. Conformity puts the nail in the coffin when it comes to the death of social advancement, so requiring couples to conform to heteronormativity may end up making the community so similar that social progress stops.
The best way to live is by “pursuing our own good in our own way, so long as we do not attempt to deprive others of theirs, or impede their efforts to obtain it.” With that said, from a utilitarian standpoint, allowing same sex couples to pursue their own happiness through being able to marry their partner increases their utility and capacity for achievement. There is no valid argument that says that letting homosexual couples marry will keep a heterosexual couple from being able to either marry or obtain their own happiness through that union. Each person is in charge of maintaining and cultivating their own happiness and health, so if being allowed to marry the person they’re with helps someone to maintain their health or happiness, then they should be able to do it. Just as “different people also require different conditions for their spiritual development,” they also may require different conditions for their own happiness that may not be in line with the current ideas of the time. It is our obligation as a society to encourage individual tastes to keep up the diversity of our community.
http://gaymarriage.procon.org/view.resource.php?resourceID=006193