Royalty works for all the reasons republicans hate it: it is immune to our mortal democratic decisions. Its appointments are made by birth and endure to death. It doesn't have anything useful to do except live in its palaces and be permanent.
It could do more. God knows I've railed about the royal family's absence at important times for this country. One of them should have been at Sir Ed Hillary's funeral. We should have seen and heard more from them when Christchurch was shattered. When the Queen speaks she could try to sound enthusiastic.
But nobody else minds. Royalty doesn't have to do anything, just be. They accept them like family, unconditionally. When one of them makes a visit, we feel graced. Admit it.
Republicans feel it too, and fight it with tedious invective against the institution and its incumbents. Charles' first marriage has given them plenty of material, though opponents of monarchy are not normally judgmental about these things.
If Diana was a mis-marriage, Camilla clearly is not. The man was visibly happier this week than we have ever seen him.
He looked at ease with his life and his long wait for the role he has rehearsed for 60 years.
If the Queen lives as long as her mother did he could be 77 before he succeeds. Too late maybe to do more than warm the throne for his engaging son.
Prince William's informality is refreshing but I think Charles would be the more interesting king. When he has ventured some mildly contentious views over the years he has not been careless. He has known exactly what he was doing.
He calculates, I think, that the monarchy is strong enough to bear an expression of some of the values he thinks important.
Charles is a baby-boomer. He was a teenager in the 1960s but didn't like the modernism that was taking hold. He retains old-fashioned tastes in architecture, education and civic design, coupled with a thoroughly contemporary fear of environmental catastrophe and an interest in alternative health treatments.
There is something in that list for several different strands of public opinion and none of the items are likely to put him strongly offside with a government. They are values that can be respected without being shared and he has the qualities to express them with no loss to a king's essential dignity.
His views are labelled "eccentric" by those who prefer their monarchs mute, but Charles is plainly not eccentric. In every other way he adheres to the formalities and traditions expected of him. His style has been too stiff until now.
A little of William's manner was evident in him this week. He didn't keep his arms strictly to himself any more. He touched people and they could touch him.
It's hard to know whether the reception for royalty is warmer in New Zealand, Australia and Canada than in countries that do not have the Queen in their constitution. The royals can draw a crowd in America too.
But there seems to be a popular sense of the constitutional bond, though we no longer want it to be as close as it was 60 years ago.
It is at least 50 years since the Queen ceased to be regarded as more than our nominal head of state. The day an English Governor-General was replaced by a New Zealander was the day we cut the apron strings.
Ever since, a New Zealander has signed acts of our Parliament, a New Zealander would play the steadying role in a tied election, a hung Parliament or any constitutional crisis. The Queen and her heirs have made it clear they would never interfere.
They never presume to speak for New Zealand and never argue the merits of the monarchy anywhere. Whenever they are asked, they say it's entirely up to us. That is why we keep them on.