Last week the Australian High Court struck down a law in the Australian Capital Territory permitting same-sex marriage. It was a good decision, but with a considerable sting in the tail. It offered a definition of marriage that allows the Federal Parliament to define marriage in practically anyway at all.

The decision defined marriage as follows: “‘Marriage’ is to be understood in s 51(xxi) of the Constitution as referring to a consensual union formed between natural persons in accordance with legally prescribed requirements which is not only a union the law recognises as intended to endure and be terminable only in accordance with law but also a union to which the law accords a status affecting and defining mutual rights and obligations.”

This says there are only two necessary elements to marriage: consent and a legal structure. But what is the difference between this and say, a business partnership?

There is no reference in the definition to the sex of the spouses, the number of spouses, whether marriage is a sexual union, or whether fidelity is any part of it.

The decision shows once more that once you ditch the notion that marriage is by its nature the sexual union of a man and a woman it can become virtually anything at all.