Complex sentence: So ardent was his opposition to slavery that on one occasion he attempted to remove some pro-slavery members of the Jacobin club because of their views; the Revolution, thought Polverel, had no room for pro-slavery sentiments.
Split into simpler sentences: So ardent was his opposition to slavery that on one occasion he attempted to remove some pro-slavery members of the Jacobin club because of their views. The Revolution, thought Polverel, had no room for pro-slavery sentiments.