No one is denying Archimedes/Ptolemy or any of these great scientists. The point the Western world must ask itself is why does it present science in such a way so as to indicate that during its Dark Ages, the scientific world was infact flourishing. Muslims built on this history and w/o us, modern science would have stagnated courtesy of popes and bishops.
It must also be thought, how come after so many years in darkness then all of a sudden Europeans made these discoveries. Not for one moment do I believe that Leonardo DaVincis discoveries were inspirational and not built upon past work.