"Neil Tyson talks about this period of time when the scientific centre of the world was Baghdad (from the Beyond Belief lectures). People of all beliefs were free to come and exchange ideas, including 'doubters' or what we'd call athiests. Out of this came a great number of scientific discoveries about astronomy, mathematics, medicine, engineering.

However something happened that led to the end of this age of science in the Islamic world. Neil Tyson describes what happened, involving a scholar (Imam Hamid al-Ghazali) who put forth the idea that mathematics was the work of the devil. This plus other things led to the collapse of that scientific tradition, and it has not since recovered.

I suspect that if the thinkers from that period saw the evidence for evolution, they would accept it gladly. Only with this attitude of accepting evidence as more reliable than dogma can a society develop intellectually, as it did in the time of Islamic science, when doubt wasn't blasphemy." - youtube