Meanings of rapid generalization in English

He asked one or two questions about them, and gave a rapid generalization of the history of France at that time.

The pre-eminent quality of each was the power of rapid generalization, of mastering and subordinating details, of grasping and applying principles and laws.

So why, because he happened to have an astonishing gift of statement and rapid generalization, should Zola be treated as though he were a monster?