science moves forward,they say,not so much through the insights of great men of gennius as because of more ordinary things like improved techniques and tools.

参考答案:

要点：本句中not so much through the insights of great men of gennius as连接状语，意思是“与其说...不如说...”。they say可以放在句首，放在句首是主谓结构，放在此处是插入语，造成句子的，翻译时按主谓结构译出。

译文：他们说，科学的发展与其说源于天才伟人的真知灼见，不如说源于改进了的技术和工具等更为普遍的东西。