Pity the poor dramatist whose work becomes a successful opera. Unless he is Shakespeare or Schiller, he will usually find that he is simply regarded as source material. So it is with Beaumarchais whose twin masterpieces, The Barber of Seville and The Marriage of Figaro, are rarely seen outside France and have been largely superseded by the more famous operas. But, with new productions of both Rossini's Barber and Mozart's Figaro at Covent Garden, it is high time we re-examined, and revived, the revolutionary writer who inspired them.
Louis XVI, with uncanny prophetic insight, said of The Marriage of Figaro: "For this play not to be a danger, the Bastille would have to be torn down first." Napoleon famously described it as "the Revolution in action". When people question, as they constantly do, the political potency of theatre, they should always remember the shining example of Beaumarchais.
The playwright's own bizarre life, from 1732 to 1799, would itself make a good opera. As a Parisian watchmaker, he invented a timepiece that was accurate to the second and small enough to fit inside a ring. As a litigious journalist, he took on a notoriously corrupt Paris magistrate, Goezman, whose reputation he left in tatters. As a French 007, he came to the aid of another of Louis XVI's secret agents, the Chevalier d'Eon, who was a robustly heterosexual transvestite. And in the 1790s he financed the first complete edition of Voltaire's works and promoted a monument to Liberty on the site now occupied by the Eiffel Tower.
As if this were not enough, Beaumarchais could be said to have helped foment two of the greatest revolutions in history. He actively encouraged the French government's support of the revolt of the American colonies, and, in 1777, organised the shipment of ammunition, guns and military equipment for 25,000 men, which led to the decisive victory at Saratoga. And, as a playwright, he created with The Marriage of Figaro a work that decisively shaped public events in his native France. Even his earlier work, The Barber of Seville, written in 1775, has its own subversive charge. Indeed one opera director, William Relton, recently suggested to me that this is just as radical as The Marriage of Figaro.
On the simplest level, Barber looks like a stock commedia dell'arte plot. Old, possessive guardian (Bartholo) seeks to marry young ward (Rosine) but is defeated by the girl's wily lover (Almaviva) and his servant (Figaro). This is the standard stuff of farce, with Bartholo as the foolish Pantalone and Figaro as the nippy Arlecchino.
But what is striking about the play - far more than the Rossini opera - is the sceptical, questioning nature of the servant and the extent to which he becomes the author's mouthpiece. In sharp contrast to the later play, Almaviva and Figaro work towards the same end: the overthrow of Bartholo's authority. But, from their opening exchanges, there is not merely an implied equality but an assumption of superior wit and intelligence on the part of the servant. When the Count dismisses Figaro as idle and dissolute, the latter instantly asks: "On the basis of the virtues commonly required in a servant, does Your Excellency know many masters who would pass muster as valets?" And it is Figaro who takes the initiative in suggesting that Almaviva insinuates himself into Bartholo's house as a drunken soldier. The servant drives the plot, the master simply executes it.
It is on The Marriage of Figaro, however, that Beaumarchais's revolutionary reputation rests. For most people the work is chiefly familiar as transmitted through the Mozart-Da Ponte opera, a sublime social comedy in which class is clearly a crucial factor. The Count, still clinging on the residue of droit du seigneur, is defeated in his designs on Susanna, whose marriage to Figaro is triumphantly achieved.
What the operagoer misses, however, is the radical fervour that motors Beaumarchais's play. The dramatic Figaro has a famous incendiary speech that generalises from his own predicament. "Because you are a great nobleman," he says to the Count, "you think you are a great genius. Nobility, fortune, rank, position! How proud they make a man feel! What have you done to deserve such advantages? Put yourself to the trouble of being born - nothing more! For the rest - a very ordinary man. Whereas I, lost among the obscure crowd, have had to deploy more knowledge, more calculation and skill merely to survive than has sufficed to rule all the provinces of Spain for a century." What is clear, as John Wood's Penguin translation shows, is that this was an assault on the hereditary principle; and it was understood as such at the time. John Wells, who did a translation for a 1974 Jonathan Miller production of the play, pointed out the dangerous parallels the play offered. "The Count, having renounced his droit du seigneur, his absolute power over his subjects, is trying illicitly to re-establish it. Louis XVI, vacillating over the liberal reforms that Beaumarchais believed would lead to constitutional monarchy, behaved in exactly the same way." And the king was intelligent enough to get the point; which is why a play completed in 1782 had to wait two years before receiving its first public performance at the Comédie Française.
But did The Marriage of Figaro really help overturn the social order? Carlyle, I think, was aesthetically wrong but historically right when he wrote in The French Revolution: "Small substance in that Figaro: thin wire-drawn intrigues, thin wire-drawn sentiments and sarcasms; a thing lean, barren; yet which winds and whisks itself, as through a wholly mad universe, adroitly, with a high-sniffing air: wherein each, as was hinted, which is the grand secret, may see some image of himself, and of his own state and ways."
Carlyle, for all his genius, was no dramatic critic: The Marriage of Figaro is a very fine play. But Carlyle was spot on when he suggested it afforded everyone an image of himself. At one point, for instance, the Count complains that "the servants in this house take longer to dress than their masters" to which Figaro replies, "Because they have no servants to assist them." It is not difficult to imagine the effect of exchanges like this on the audience at the Comédie Française, where the play ran for 100 nights; and, as Carlyle says: "All France runs with it, laughing applause."
Beaumarchais can be described in many ways: as a fortune-hunting adventurer, a raffish opportunist, a calculating survivor willing to flatter the powerful when he needed their patronage. But he was, above all, an instinctive libertarian whose whole life, as Wood writes, "was an assertion of individuality against the constraints of social privilege". That is why he helped shape the 18th century and why he still speaks to us today: he realised nothing was more subversive than comedy. And, good as it is to find the Rossini and Mozart operas he inspired back at Covent Garden, it would be even better to find his plays given their theatrical due.
· Il Barbiere di Siviglia is in rep until January 14, Le Nozze di Figaro opens on January 31, both at the Royal Opera House, London. Box office: 020-7304 4000