But the irony is "democracy" was mostly used as a term of condemnation and an example of chaos and failure for two thousand years, right into the late eighteenth century.
And now it also means something almost entirely different from its original meaning of the citizens of Athens direcly ruling themselves. There is a "chasm", Dunn says, between that and our modern representative democracies.
Indeed, it was Robespierre more than anyone else who brought the term back into circulation, and the left wing of the French revolution such as Babeuf who wanted it to mean equality.
By egoism Dunn means the modern self-interested capitalist world of Alexander Hamilton and the Manchester Liberals. In the second world war and cold war, however, that was a thin basis for loyalty. In the fight against fascism and communism, western leaders needed something more - a renewed stress on democracy as an ideal.
Democracy has altered its meaning so sharply since Babeuf because it has passed definitively from the hands of the Equals to those of the political order of egoism.
And the horrors of revolution from Mao to North Korea to the Khmer Rouge elimated other serious competitors for forms of state and principles of legitimacy.
In the last instance, and in the face of intense suffering, they needed it above all to focus their citizens' allegiance, and to define a cause worth fighting to the death for in a way that the order of egoism could never hope to provide for a good many.
And in the meantime democracy as a value undermines most other claims to power or privilege, as Obama or Cameron or Merkel know.
In these later episodes, in all their desolation, the rage for equality becomes for a time something very close to a rage against the reality of other human beings or the very idea of a society.
It is an observant and trenchant book. What stays with me, though, and which is relevant to this blog project, is a renewed focus on the basis of legitimacy. Why do we see current arrangements as legitimate? In large part because that 'egoist' self-interest capitalist framework has delivered.
It dissolves the pretensions of intellectuals and corrodes the claims to authority of all who happen at the time to exercise political authority anywhere in particular.
In order to durably shift the nature of the economy, however, the basis of legitimacy would likely have to shift again. And that is a difficult and dangerous matter.
It reminds me of Phillip Bobbit's book The Shield of Achilles, which traces the history of the states system over the last five hundred years. He sees it as a story of successive principles of legitimacy - and therefore forms of state - evolving with epochal wars dividing them. He sees the "market state" as the culmination of that process in our own time.
But if, as I think, we are reaching the limits of the market as a device which can underpin the economy, then that spells potential trouble. As always, it is not because there is anything wrong with the market. It is just that it is a tool which cannot accomplish all our human purposes if we largely have material abundance and the nature of our needs starts to shift.
So this suggests more room for blogging on legitimacy and the potential for disorder if we are seeing a phase shift in the nature of the economy and the state.