The revisionists are the ones who try to credit third world people with all sorts of scientific and cultural achievments, which they then miraculously lost or forgot and went back to living in goatsh!t huts with their livestock, because the evil Europeans stole their culture and they just never could find it again.
Careful, there, Steve, or someone is going to point out something little like the fact that the Romans worked concrete, but it wasn't re-invented until the 1800's, or that the Chinese were drilling for natural gas in the 500's, and piping it dozens of miles to cities for use.
Knowledge has been lost by many civilizations throughout history, often after their centers were destroyed by "uncivilized hordes". Incidentally, the center of much Muslim knowledge was Persia, not Arabia. Persia, of course, was knocked off it's perch for the most part by the Mongols. FWIW, Dutch.
