So far, I've focused on national identity (and the perceived "threat" to it) in my posts on why Su'a William Sio should be allowed to swear his oath of office in Samoan. But there is also a strong liberal argument in favour. The most basic principle of liberalism is the harm principle, expressed by John Stuart Mill as:
the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection. That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others.So, how does someone being sworn in in Samoan harm people? How does it hurt me? The answer is that it doesn't, any more than people swearing on the Bible rather than affirming does. It doesn't even matter that I can't understand it - it's a ceremonial occasion, and everyone knows what they are saying anyway.
Neither (as alleged by some of DPF's sewer-dwellers) would it be some sort of "special right" for non-English speakers; instead it is the same right that Anglophone New Zealanders take for granted: the ability to conduct official business in the language of their choice. We recognise that right already to a large extent - a lot of government forms are translated into multiple languages to make them accessible to as many people as possible (see for example the range of information available for electoral enrolments). We should extend that principle to oaths and declarations as well.