Bacteria and viruses know no frontiers. The attempts to infect public fear of the coronavirus epidemic with xenophobic and racist superstition would be pathetic, if it were not for loutish electoral speculation. Today the Chinese confront it, but should it be a pandemic tomorrow the hunt for those infected will point to migrants, who will once again be scapegoated on the pages of Facebook. Yet the bourgeoisie, in the centuries during which it still remained a revolutionary class, knew how to shed a light of clarity through the mist of thousand-year-old superstitions. Renaissance men founded the scientific method; the intellectuals of the Enlightenment changed the view of the world; pioneers of science and technology accompanied the industrial revolution in mechanics, steam energy, chemistry and electricity; heroic doctors founded modern medicine, going so far as to experiment with vaccines on themselves in order to make it possible to face terrible diseases. Finally, science married la