Several versions of the quote began to be cited in Japanese books on the military or religion as the words of Einstein (1879-1955) in the 1950s.

But all those books and Web sites failed to provide a source for the quote.

Nakazawa also wondered why someone like Einstein, who dealt with the laws governing the universe, would praise Japan's emperor system and its uninterrupted lineage, let alone refer to God.

In his search for the quote's root, Nakazawa found a 1956 publication that first mentioned it as Einstein's.

The professor dug further back, where he found a passage with much the same content in a book published in 1928.

The book, whose title translates as "What country is Japan like," was written by Chigaku Tanaka (1861-1939), a religious leader.

Tanaka, a nationalist who advocated unifying the world under the emperor, influenced ideas for Japan's polity before and during World War II.

In his book, Tanaka quoted the passage as words of Stein (1815-1890), whose ideas helped Japan in compiling its Meiji Constitution.

Nakazawa examined records of Stein's lectures, from which Tanaka was said to have learned his ideas. The University of Tokyo professor said he found no evidence that indicated the German said anything to that effect.

Nakazawa says Tanaka likely presented his own ideas in discussing Stein's thoughts, and people mixed up the two.

That probably started the chain of quotes, he says, during which "Stein" somehow transformed into the more familiar "Einstein."