In his introduction to No Need for Geniuses the geneticist Steve Jones claims to be indulging in “what the French call, in an inelegant but precise phrase, vulgarisation scientifique”. What follows is an ingenious guidebook to the scientific past of Paris, written in lucid, erudite prose that is certainly not vulgar in the English sense.

The Eiffel Tower is the starting and end point of Jones’s tour. It was opened in 1889 to celebrate the centenary of the fall of the Bastille and its designer, Gustave Eiffel, hoped it would symbolise “the century of Industry and Science in which we live, and for which the way was prepared by the great scientific movement of the end of the 18th century”. Originally, the tower contained a physiology laboratory where researchers examined the effects on tourists of climbing the steps. It also housed an observatory and weather station and was the site of the world’s first radio transmission: so much more edifying than the 300-metre-tall sculpture of a guillotine that was one of the competing proposals submitted for the centenary celebrations.

The French Revolution exerts a centripetal force over the story of science in Paris. Jones argues that, “as its system of government creaked and fell, Paris had more experimenters and theoreticians than did the rest of the planet put together. In the heady days around the fall of the Bastille, the city was saturated in science.” He assembles a cast of philosophes who entered revolutionary politics in the hope that it could lead humankind to an era of inevitable progress by advancing the natural and social sciences.

The chemist Antoine Lavoisier “was the epitome of that era’s marriage of technology and politics”. A wealthy nobleman and friend of Benjamin Franklin, as well as a joint discoverer of oxygen, hydrogen and nitrogen, he strictly divided his working day between his laboratory and public affairs. His Traité élémentaire de chimie, which laid the foundations of modern chemistry, was published as the revolution began in 1789. Among many other achievements, Lavoisier invented a copper centrifuge for refining saltpetre into gunpowder. During the revolution the oldest church in Paris, the 6th-century abbey of Saint-Germain-des-Prés, was renamed the Atelier de l’Unité and became a refinery for up to 100 tons of saltpetre a day. In 1792 a great armaments festival celebrated the triumphs of the chemists, and Lavoisier’s centrifuge was raised up under a banner proclaiming “Mort aux Tyrans” (“death to tyrants”). Yet just two years later, he was guillotined, accused of selling adulterated tobacco and

of profiting from collecting or “farming” taxes under the Ancien Régime. Jones takes his title from the probably apocryphal judgment at Lavoisier’s trial: “La République n’a pas besoin de savants.” He translates “savants” as “geniuses”, but “scientists”, “scholars” and “show-offs” are other candidates. The radical revolutionaries had a blanket dislike for all who distinguished themselves from the crowd.

The Marquis de Condorcet was another savant as deeply engaged in politics as he was in advancing knowledge. A mathematician and permanent secretary of the Académie des Sciences before the revolution, he was one of the first politicians to call for a republic after 1789. An early feminist, he argued for the extension of the new Rights of Man to women. He claimed that never a day went by without him thinking about political science. He was imprisoned during the Terror and found dead in his cell, poisoned either by himself or by one of his guards, his Sketch for a Historical Picture of the Progress of the Human Mind left incomplete. Continuing his tour of the city, Jones notes the empty coffin honouring Condorcet in the Panthéon: his bones are lost.

By contrast, the bones of the incendiary journalist Jean-Paul Marat were removed from the Panthéon in disgrace. Before the revolution Marat conducted research into light, heat, electricity and sexually transmitted diseases. He translated Newton’s book on optics into French, but was thwarted in his ambition to become a member of the elite Royal Academy of Sciences under the Ancien Régime. After 1789 he started to hope that the academy would be destroyed and he would find himself “installed in the place which I deserved”. When Charlotte Corday assassinated him in his medicinal bath, he became revered as a revolutionary martyr, but at the end of the Terror, which he had done so much to encourage and promote, his coffin was taken from the Panthéon to

a more modest resting place.

Jones pays tribute to the scientist, pharmacist and nutritionist Antoine-Augustin Parmentier, who began to proselytise the potato in France two decades before the revolution. His efforts, however, were not enough to end the widespread hunger that precipitated regime change. He hosted a 20-course potato banquet and invited Benjamin Franklin; he even persuaded Marie Antoinette to wear a bouquet of potato plant flowers, but it was not until the height of the Terror that the potato was accepted as sustenance for the poor. The revolutionary cookbook La Cuisinière républicaine contained more than 30 potato-based recipes.

Jones argues that as the world needs to double its agricultural production over the next half-century to support the expanding population, we need a new Parmentier. Thomas Jefferson, the first US ambassador in

revolutionary Paris, noted that “the greatest service which can be rendered any country is to add a useful plant to its culture” (while president, Jefferson was served “potatoes fried in the French manner” at the White House). Of the 400,000 known species of plant, fewer than 300 have ever been used as staple foodstuffs for human beings. A new Parmentier, experimenting with artificial selection of the kind used on the potato, could provide a more secure benefit to mankind than any possible political change. Contra the revolutionaries, we do need geniuses and we need them fast.

Politics is a dirty business and in the short run, it can comprehensively disrupt collaborative science. During the extremes of the French Revolution many scientists were imprisoned or murdered. The lucky ones, such as Bernard de Lacépède, who studied physics and fish, escaped into hiding: “I forgot the world and saw the universe,” he wrote. Louis Bosc, an entomologist, took to the hills of Montmorency, where he studied forest spiders. The chemist Antoine Fourcroy survived by seeing nobody, refusing all invitations and keeping himself “outside every faction”. But in the long run, science triumphs over politics. Posterity has forgotten most of the causes and details of the factional fights that led to bloodshed and misery: the scientific discoveries that changed the world for the better are remembered.

At the heart of the French Revolution there is a puzzle about why so little progress was made in the social sciences compared to the natural. Lavoisier’s contemporaries were excited by his advances in chemistry, and some of them thought it would be possible to make similar advances in understanding society and politics. Condorcet died certain that such breakthroughs were on the horizon – but the social harmony, equality of rights and opportunities that he envisaged have never been realised, not in France, or anywhere else.

Ruth Scurr’s books include Fatal Purity: Robespierre and the French Revolution and John Aubrey: My Own Life (both published by Vintage)