The best choice in response to whether the author successfully supports the claim that "In no other department is a thorough knowledge of history so important as in philosophy" is:
1. Yes, because he gives examples of why knowledge of history is vital to philosophy.
The author discusses the relationship of philosophy to both historical science and art, emphasizing the importance of historical knowledge in understanding the context and development of philosophical thought. The passage highlights the unique characteristics of philosophical systems and their relative permanence, suggesting that a knowledge of history is crucial for engaging with philosophical ideas. Therefore, the argument supports the claim rather than contradicting it.