What was Edward Abbey known for, according to Twilly?

Edward Abbey was known for his passionate advocacy for environmental issues and his radical ideas concerning nature and public lands. He often used provocative and incendiary language to challenge the status quo and to advocate for the protection of the American wilderness. His writings, particularly in works like "Desert Solitaire" and "The Monkey Wrench Gang," reflect his belief in direct action and civil disobedience against environmental degradation. This aligns with the notion of "bomb throwing ideas and principles," which suggests a bold and disruptive approach to activism and thought.

The other options do not align with Abbey's reputation or contributions. While he engaged in political discourse through his writings, he was not known as a politician. Abbey's focus was on environmental issues rather than historical fiction, and he was not a scientist in the conventional sense, although he had a deep understanding of ecology and conservation. Therefore, the characterization of him as one who "bomb threw ideas and principles" effectively encapsulates his approach to environmental advocacy and his role as a writer and thinker.