Complex sentence: Cuvier stuck to "positive facts" of science and refused to flirt with hypotheses and unsupported ideas, as he often worried this kind of thinking would lead to unrest and disorder in France as the French Revolution had torn through only a few decades before.
Split into simpler sentences: Cuvier stuck to "positive facts" of science and refused to flirt with hypotheses and unsupported ideas. This attitude sprang from worries that this kind of thinking would lead to unrest and disorder in France as the French Revolution had torn through only a few decades before.