Complex sentence: The reader is left to form an impression of Jim's interior psychological state from these multiple external points of view; but mere facts are inadequate to explain the human condition, as Marlow remarks of the trial: They wanted facts.
Split into simpler sentences: The reader is left to form an impression of Jim's interior psychological state from these multiple external points of view. But mere facts are inadequate to explain the human condition, as Marlow remarks of the trial: They wanted facts.