Would you want your offspring to marry a politician? If not, why not? The customary answer is, because politicians are hypocrites. They lie, dissemble and pretend to be or do what they are not to attain office and wield power over others. What could be more reprehensible?

Many things, is David Runciman's answer, including hypocrisy's overrated antithesis, sincerity. To say he is a fan of hypocrisy is an understatement. He loves it, studies it, defines and cross-references it, deploring those who fail to see its virtues in binding together the social contract. “Hypocrisy,” said Rochefoucauld, “is the tribute that vice pays to virtue.” It is a noble tribute. Where would we be without it?

Runciman is a political philosopher whose specialism is the psychology of politics. In a previous work he savaged the “politics of good intentions”, such as Tony Blair's thesis that his purity of purpose in waging war on Iraq and Afghanistan justified the act, however incompetent its execution or failed its outcome. Naked power was ill-clothed by moral excuse.

Now he turns his attention to another facet of the same syndrome, but comes near to drawing an opposite conclusion. What are we to make, asks Runciman, of the mendacities, half-truths and double standards that appear to be the necessary oil on the wheels of democracy?

Conventional liberal wisdom regards hypocrisy as the most deadly of sins and newspapers demand daily that we compel politicians to “wriggle free from the hold it has on us all”. Leaders are excoriated for lauding family values and failing the bedroom test. They deplore sleaze, yet are its embodiment when given half a chance.

Blair and Gordon Brown made their careers from opposing Thatcherism, but ruled as Thatcherites and celebrated its author. They professed to a concern for the poor, but enriched the wealthy. They joined America, the home of freedom and self-determination, in imposing their will on foreign states by force of arms. In a nutshell, politics is the profession of not practising what it preaches. It is fair game for investigative journalism. We must be able to trust our rulers.

That might be fine, says Runciman, were there evidence of any government in history that could rule without hypocrisy. The kingdoms of mankind operate on the basis of compromise or they descend into anarchy, and the central compromise is that rulers pretend to accord with the views of the ruled. Cromwell preached the Christian virtues of peace and forgiveness yet visited fire and brimstone on his foes. Army padres preach the brotherhood of man yet call on “Heaven to bring us victory”.

Most of Runciman's book comprises studies of writers from Hobbes and Machiavelli to Bentham, Trollope, George Eliot and Orwell who wrestled with the concept of the “white lie” and the double standard, with novelists tending to be harsher than philosophers. Only Trollope seems sympathetic to MPs who feel “bound to let the outside world know that all corrupt practices at elections were held to be abominable”, while knowing well “what had taken place at their own elections.”

The truth is that if every candidate for office took a Tolstoyan position and said (sincerely) that power was much overrated and a ministry's outcome was mostly decided by fate, nobody would vote for anyone. The politics of optimism requires the supremacy of hope over experience.

This so-called “democratic hypocrisy” forms the compact of majority rule. As Hobbes pointed out, politics is a necessary parade of masks, pretences and selfdelusions. Only the totalitarian ruler is sincere in asserting the supremacy of power. “There is no way of breaking out from the hypocrisy of political life,” says Runciman, “and all attempts to find such an escape route are a delusion.”

Since Runciman is not a cynic, he must tackle the obvious question of where we go from here. “When is hypocrisy worth worrying about, and when not?” Nor is this an abstract question. With characteristic vigour, he cites the current race for the American presidency, riddled with hypocrisy about religious belief, just war, taxation and climate change. There could be no greater hypocrisy than to pledge a reduction in carbon emissions while conceding to lobbies intent on increasing them.

Runciman at this point is less than wholly satisfactory. His essential message is that politics is complex, indeed the most complex of all human activities. We therefore need to know “what sorts of hypocrites we want our politicians to be, and in what sorts of combinations”.

This involves much dirty work. We must grade their mendacities into first and second order hypocrisies. At one level we accept such white lies as are implied by “the basic standards of social conformity...politeness...a desire not to hurt someone else's feelings...good manners”. We promise this and deny that because otherwise life is just not liveable.

At another level, we want to be sure that leaders who make promises (which we may acknowledge as hypocrisies and thus be complicit in) are aware of their hypocrisy, like Trollope's ever-anguished Phineas Finn. In other words, we must appreciate the central paradox, that our rulers be sincere in their insincerity. The general (or the party leader) who predicts victory in a battle certain to end in defeat at least owes it to his followers to plan for that defeat. It is what Orwell called “benign self-deception”.

Although Runciman is often opaque and sometimes disappears into a miasma of his own paradoxes, this is a useful corrective to much journalistic sanctimony. There is no point in denying political hypocrisy “by denouncing it, or taking sides, or seeking some sort of personal insulation from it”. It is embedded in society and ideology. Most (if not all) wars and religions are riddled with the language of hypocrisy. It is a cloud swirling round everything we do and say. The compromises of even so thoughtful a politician as Barack Obama, says Runciman, are “not hypocrisy but instead a form of principled pragmatism”.

The difficulty, and it is immense, is that of which Hobbes warned. When a proclaimed pragmatism strays into self-deception and we lose sight of what is truly at stake, hypocrisy loses its virtue and becomes toxic.

Runciman's last book placed politicians firmly on the hook of truth. Now he comes near to letting them off it. He draws a fine philosophical distinction between good and bad hypocrites, but not one that is much help to the mere voter. I am still tempted to revert to HLMencken and treat the whole bunch as rapscallions.

POLITICAL HYPOCRISY: The Mask of Power from Hobbes to Orwell and Beyond by David Runciman

Princeton University Press £17.95 pp286 Buy from Books First £16.16 with free delivery

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