不說第三類，前兩類有共同點，即先設的價值取向。

But it is understandable since Needham was a modern westerner and Qian was a modern scientist.

Yet, their question wasn't a fair one. It is hard to ask why something didn't happen. The fair question would be: why modern science has developed (or "invented") in the west? I believe Einstein once pondered over this question though perhaps just briefly.