The bare facts of the life of Jean-Jacques Rousseau are not reassuring. Born in Geneva in 1712, he lost his mother as an infant; his relationships with women, often platonic, sometimes masochistic, seemed doomed from the start. His father, a Calvinist watchmaker, provided little reason to stay at home, and by his mid-teens Rousseau had set out on a series of attempts to make a living, including petty thievery, all of which ended unhappily.
Eventually, he settled on copying music and practiced this lowly but demanding trade for the rest of his life. His relationship with his common-law wife produced five children, all sent to a foundling hospital. He converted to Catholicism and then back to Genevan Calvinism until his final exile from his native city cast him adrift.
And yet, he taught himself to write and the publication of his controversial writings, which made him a celebrity, did nothing to settle him down. Even Napoleon found his influence a threat to the peace of France. Samuel Johnson thought him, intentions aside, a "very bad man."
As Leo Damrosch, the Ernest Bernbaum professor of literature at Harvard University, so vividly demonstrates in his new biography, Jean-Jacques Rousseau: Restless Genius, Rousseau was full of contradictions.
This bad father wrote "Emile," a guide to child-rearing that discourages discipline and argues that "the best households are always the ones in which the woman has the most authority"; this irascible dependent (he strained the charity of even his most devoted supporters) wrote "The Social Contract," a hymn to equality and the sovereignty of the people; this tortured lover wrote "Julie," the best-selling novel of the century in which he celebrated chastity and renunciation; and this alleged freethinker echoed Augustine's title (and much else) in his "Confessions," while concluding late in life that the answer to the question, "what am I," had eluded him.
Damrosch starts where many would finish: Rousseau's intentions as a writer. This gesture of good faith pays hefty divi-dends. Rousseau's goal as a writer was to confront the contradictions "that seem inseparable from our experience." In Damrosch's portrait, we see Rousseau as he understood himself: a man of paradox.
At several points Damrosch compares Rousseau to that "other run-away apprentice who achieved fame" Benjamin Franklin. Franklin believed "that we can do anything we want, but only by creating an attractive social persona, imprinting it through habit until it becomes second nature, and using it to get other people to cooperate."
Rousseau, on the other hand, believed "there was only one nature," as Damrosch puts it, "the one that was betrayed when civilization was invented, and he held that by honoring it we can be true to our own authentic being. But the cost was isolation."
For Rousseau, isolation in wild nature - he was an indefatigable walker and late in life a passionate botanist - was a great consolation.
Rousseau said, "I would rather be a man of paradoxes than a man of prejudices." The idea that a human being, stripped of prejudice, revealed paradoxes is a powerful idea - and far from sentimental.
In practice, Rousseau did not disagree with those who pointed out his contradictions (timid/merry, caustic/humble, mistrustful/confiding).
Damrosch explains some contradictions as the result of Rousseau's experience. For example, he quotes him as admitting "I have a daring nature and a timid character," and explains that "social life had replaced his natural confidence with bashfulness and hypersensitivity."
Reading Damrosch's sympathetic portrayal of Rousseau's often self-imposed troubles, it sometimes seems that Rousseau chose the path of failure as a kind of hermeneutic - a way to see more reality than conventional success would have allowed.
At a time when class was still sacred (in the following quote, "état" means "status"), he wrote: "Without any état of my own, I've known and lived in them all from lowest to highest, excepting only the throne." And yet today most regimes honor, often in the breach, his idea of the sovereignty of the people.
Late in life Rousseau was given to reading his banned works aloud to friends, sometimes for many hours at a stretch. His last reading was of the "Confessions" in 1771. "Most listeners were too shocked or embarrassed to say anything at all," Damrosch writes.
Breaking the silence, Rousseau said: "I declare openly and without fear that whoever, even without reading my writings, will examine with his own eyes my natural disposition, my character, morals, inclinations, pleasures, and habits, and can still believe me to be a dishonorable man, is himself a man who ought to be choked."
Unforgivable - or heroic? Damrosch's Rousseau has the courage of his own absurdity. While accepting his contradictions, he prayed to be free of them.
(Rousseau's profound and persistent piety needs scholarly attention; Damrosch's account leaves no doubt about the depth of Rousseau's response to a sacred reality beyond all his troubles.)
For this reader at least, Damrosch's Rousseau, by embracing impossibility, refused the temptation which has done so much harm - the temptation of certainty. Damrosch's superb biography succeeds in shattering prejudices and illuminating paradoxes; it sets the table for many new conversations.
• Tom D'Evelyn is an editorial consultant in Providence, R.I.