I think the parent poster's comments are still valid. There was a good article yesterday about Antoine Lavoisier, the father of modern chemistry, who was killed unnecessarily during the French Revolution (but not during the dark ages). Someone said it most probably set back chemistry 20 to 50 years. It happened, often. Or Galileo and his rotation of the planets. Many people consider Europe to have been largely ignorant during the dark ages. I'd definitely agree.