Egypt turmoil: Coup or no coup?
So when is a coup d'etat not a coup? Or to put it another way, is there such a thing as "a good coup", which means of course there must also be "a bad coup"?
And if so where does the Egyptian army's ousting of President Mohammed Morsi stand on this scale? Which one was it?
In one sense, of course, it is a doubly irrelevant question. Does it matter?
For one thing outside countries can do very little about it - even the United States with its much-vaunted ties to the Egyptian military.
And in a region as troubled as the Middle East, nobody has the luxury of holding Egypt at arms-length even if they wanted to.
Talk about Washington calling into question its financial support for Egypt - and particularly its military - is just that, talk.
So at one level the discussion of "a coup, or no coup" is - as one pundit I encountered going into a TV studio this morning rather disparagingly described it - a question for Western commentators to agonise over.
But in another important sense it does matter.
It has coloured the initial responses of key Western governments - like President Barack Obama, for example, speaking of the US being "deeply concerned" by the Egyptian armed forces' actions.
What foreign governments say will be remembered by the Egyptian people, and US policy in the run-up to the military's take-over has prompted strident criticism from both pro- and anti-Morsi camps.
This caution has been reflected in British statements too, though Foreign Secretary William Hague put his finger on the problem when he pointed to the dual nature of the events in Egypt.
This was, he said "a military intervention in a democratic system," but equally, he said, "it was a popular intervention".
So putting these two aspects together, does this then make it a "good coup"? The pragmatic view would be to look to see what emerges from it - and some hard-headed realism is probably in order.
The Egyptian military played a key role in politics before President Hosni Mubarak's departure; it stood centre-stage after the upheavals of the Arab Spring; and as this latest crisis demonstrates it has again emerged from its barracks to enforce what it sees as the national interest.
The military shadow over Egyptian politics is not going to disappear any time soon. Look how long it took for the Turkish military to be marginalised in Turkish politics.
A democratically elected president has certainly been removed from office by the military, and that by anyone's definition sounds like a coup.
But again, one set of elections, whatever the popular yearning for change, did not make Egypt a democracy.
It was, like so many other countries in the region, on a journey to democracy: establishing new roles for key institutions; creating the representative bodies of civil society; and above all creating the habits of democracy in both people and political leaders.
It was - say some analysts - precisely because he himself had not imbibed the democratic habit sufficiently that President Morsi found himself challenged on the streets.
By this reasoning this was an atypical coup in a very imperfect democracy.
Right or wrong is for the pundits and the historians. Governments in the region and diplomats in the wider world have to deal with the reality of the new Egypt.
Everything now depends upon the transition to a renewed democratic order.
Western leaders have made it clear that this needs to be speedy, transparent and inclusive.
Huge questions remain.
How will the Muslim Brotherhood be represented in the new institutions? How much popular support will it have?
And, crucially, what message will its Egyptian experience send to similar groups around the region.
Will their conclusion be to better burnish their democratic credentials, or to decide that having won an election in Egypt they were simply robbed of power - thus calling into question their whole commitment to democratic politics.