1. "At another time he thus expressed his method of study:"I keep the subject continually before me, and wait till the first dawnings open slowly by little and little into a full and clear light. 另一次,他这样表述他的研究方法:“我从未停止探索的脚步,当我看到第一缕曙光后,坚定的信念支持着我最终看到了清晰的世界。”