On How a Good Law Prevents a Harm

I read an interesting article at Popehat today which opposes North Carolina's Amendment One, in which voters there have been asked whether they want to add this text to the state's constitution.

Marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this State. This section does not prohibit a private party from entering into contracts with another private party; nor does this section prohibit courts from adjudicating the rights of private parties pursuant to such contracts.

The content of Patrick's argument against the law is encapsulated as follows.

All laws restrict freedom in some fashion.  All laws harm some subset of people within the body public, by punishing them for exercising their freedom, but sometimes that's justifiable.  A good law is one that protects the public, or individuals who make up the public, from a discreet, identifiable harm, while doing as little damage as possible in the process.

A heterosexual marriage is not harmed when a gay couple marries, so forbidding gay marriage does not prevent a harm.  Nothing is harmed by gay marriage.  So Forbidding it is a harm.

Unfortunately, this amendment has now passed, and North Carolina joins 28 other states that explicitly forbid same sex marriage in their constitutions.