Final answer:
Jimmy's rebellious nature is evidenced by his expulsion from Oxford for publishing a controversial pamphlet and his interest in radical literature and skepticism towards Christianity during his school years.
Step-by-step explanation:
The character of Jimmy seems to exemplify the qualities of a natural rebel, as indicated in the text excerpts provided. One incident pointing to his rebellious nature comes from Shelley's life, where he displayed a tendency towards dissent right from his school years. Specifically, the first incident is his expulsion from Oxford for refusing to answer questions and publishing the controversial pamphlet "The Necessity of Atheism."
The second incident illustrating Jimmy's rebellious streak can be found in a text reference that speaks of his skeptical approach towards Christianity and how, during his time at Eton, he was influenced by radical literature and the works of philosophers like Hume and Voltaire.