反动势力使得改革举步维艰。

The forces of reaction made change difficult.

居维叶一只眼睛望着《创世记》，另一只眼睛望着自然界，为了取媚于迷信的反动势力，于是用化石证实经文，用猛犸颂扬摩西。

Cuvier, with one eye on Genesis and the other on nature, tried to please bigoted reaction by reconciling fossils with texts and by making mastodons flatter Moses.