In the debate over assisted suicide, one thing that has bugged the heck out of proponents has been the use of secular arguments by the opponents of Seymour's law. Here is one of such pieces by Listener writer Graham Adams, for example, having a crack at Catholics for not being more overtly religious in their reasoning. Members of Parliament made similar criticisms of members of the public who had negative submissions to make on the bill.

Of course, if people of faith had shown up citing the authority of sacred scripture as their primary argument then it's fair to say the same people wouldn't have been very happy about that either. The accusations of theocracy would have been swift and certain. So perhaps it is simply the view of such critics that citizens with religious sensibilities must simply be banished from the public square altogether.

Secularists often bristle at the idea morality is inseparable from religion. And they have a point here. The mainstream Christian view for centuries has been that morality can be discerned through human reason.

Theft presents a useful illustration. A breach of the seventh commandment, stealing can be seen as an action that offends God and so Christians (and others) see theft as a sin. However, the effects widespread theft would have on the fabric of society are such that is would also have to be discouraged and punished by the law even if we all agreed that God did not exist.

The inviolability of human life is also a religious precept that reflects the way religious people consider that every single person, no matter how high or low their condition, contains the image of God's glory. The importance of this precept, however, is entirely intelligible without direct reference to that justification. In other words, you don't need to go to mass to understand why it is that murder ought to remain outlawed.

New Zealand society is, like most of the West, post-Christian. Whatever temporal influences institutional religion may have wielded in the past, those days are behind us now. And, as a result, when the religiously observant enter into public debate they must frame their arguments in secular terms.

So it would foolish for church leaders to argue, for example, in favour of a law compelling people to go to confession at least once a year. Or to refrain from red meat during lent. Those are disciplines that only really concern people's relationship with God and not each other.

Euthanasia is not an issue of that nature. It is an argument around the boundaries of a precept that so universally accepted that it's the first right enumerated in the New Zealand Bill of Rights Act 1990. And while their faith may affirm their stricter interpretation of that right, the issue remains something that is capable of being understood and debated in secular terms.

Which is what religious people have, for the most part, been doing.

It is a good rule of thumb to try not to second-guess the intentions of others. While it can be tempting to short-circuit an argument by ignoring what the other person has actually said, in favour of what you think really motivates them, there are few things more poisonous. That goes double for heated debates - like the one we are continuing to have on assisted suicide.