>A lot of good math and science was done before the Enlightenment - look at Newton or Euler or Descartes, for example. The scientific environment often operates rather independently of the political environment - the Soviets also had high-quality science going on.

Newton and Descartes are considered part of the Enlightenment, and you cannot conduct high-quality science while the politicians are telling you that conclusions like "evolution operates by natural selection" (re: Lysenkoism) or "there's no evidence for a natural hierarchy of races" (re: both current and previous incarnations of racism) will lose you your job.