Any autumn snapshot of this year’s momentous Arab upheavals will certainly capture the wretched end of Muammer Gaddafi. But it will also highlight two radically different ways of doing the business of government, on display this weekend in the Arab spring’s democratic debut in Tunisia and (not at all on display) in the secretive and theocratic kingdom of Saudi Arabia.

Electing a constituent assembly in what could set a benchmark for Arab countries that topple their tyrants, about 90 per cent of eligible Tunisians turned out to vote. Great uncertainty lies ahead for their revolution, as well as those they helped ignite, in Egypt, Libya and Syria. But the joyful embrace of suffrage by people who had suffered decades of despotism has set a tone.

In Saudi Arabia, the death of the ageing Crown Prince Sultan, by contrast, sets in motion a royal succession reminiscent of the gerontocratic Soviet politburo as Leonid Brezhnev began to fade. The future of the kingdom is pretty much already in the hands of Prince Nayef, the ultraconservative interior minister, 77, now likely to be installed as crown prince and to take the throne once the also aged and frail King Abdullah leaves the scene.