"The evolution of political thought in this relatively isolated island nation during the period in question is unique to the point of being somewhat freakish."

This gives a reader pause. Freakish? The judgment is historian Hiroshi Watanabe's in "A History of Japanese Political Thought, 1600-1901," his 2010 book whose title defines "the period in question."

"Nor," he adds, "did it (Japanese political thought) have much impact on thought outside the Japanese archipelago. In this sense, it may call to mind the strange animals of the Galapagos Islands, pursuing their own evolutionary path."