After 2,000 years, Bolyai had clearly demonstrated that Euclid's fifth axiom was not a consequence of the other four, but he was staggered, and somewhat upset, to find that the greatest living mathematician — Carl Friedrich Gauss — already knew it. Gauss was a man with a huge reputation who didn't want to get into arguments with his contemporaries. The consensus among experts was that the fifth axiom was provable — this was an item of faith — so he had decided to leave his work to be published after his death. Only when a man less than half his age had shown the consensus was wrong did Gauss admit he already knew that it was wrong. 

Now we have a consensus that CO² emissions are the cause of global warming, and contrarian voices are shouted down. Politics has entered the scientific debate, and knights in shining armour have risen to protect us, even if like dear old Don Quixote they are merely tilting at windmills.