Antoine-Laurent de Lavoisier (1743-1794) was one of the greatest scientific lights of his time, the so-called "Father of Modern Chemistry," who, among many other things, made important contributions to the chemistry of life. He was very much a person of the Enlightenment, who believed in the scrupulous use of language, the primacy of reason over the emotions, and the empirical foundations of truth.
Of one of his theories he had this to say: "Perhaps I shall be obliged to make some modification in the doctrine that I have presented…I shall not hesitate to modify my opinions, even to reverse my steps, if new experiments force me to abandon the first course I have followed."
Lavoisier was also a public-spirited man who unfortunately got caught up in a tax scandal that was fiercely prosecuted by the revolutionary courts during the time of the Terror. It is said that he appealed to the judge against his death sentence by invoking the contributions he had yet to make to science. The judge is said to have responded, "The Republic has no need of scientists."
As far as I have been able to determine, the judge's remark is apocryphal. But like Galileo's equally famous apocryphal remark at the end of his trial -- "And yet it moves" -- the myth has the ring of truth.
Revolutionary France under the architects of the Terror was a "republic of virtue." That is to say, Robespierre and his ilk were so convinced of the righteousness of their cause that counter-opinions were seen as not just contrary but treasonous. Lavoisier's head ended up in a basket along with hundreds of other real and imagined enemies of revolutionary "virtue." The mathematician Lagrange said: "It took them only an instant to cut off his head, but France may not produce another such head in a century."
Republics of virtue -- where virtue is understood as a passionate, emotional, unwavering and righteous conviction of Truth -- have no use for science. As Arthur Donovan writes in his biography of Lavoisier: "Reason and methods for reliably connecting interpretation to reality counted for little in a world preoccupied with fear, anxiety, and a desire for retribution."