What and for whom are scientific controversies useful?

Scientific controversies have probably always existed; Copernicus, Darwin or Pasteur fought to impose their results. From the end of the 20th century onwards, scientific controversy emerged from its ivory tower. Whether we are talking about endocrine disruptors, vaccines, global warming, electromagnetic waves, GMOs or nanotechnologies, public opinion and lobbies have become major players. The factory of doubt is undermining scientific knowledge.