Perhaps every country has something to learn from its ancestors. But when the roots of time-honored wisdom are dubious, should such wisdom still be taught to schoolchildren?

Now Edo shigusa, or actions and behavior apparently practiced and handed down from ancestors in the Edo Period (1603-1868), have sparked controversy amid recent moves by schools to introduce such etiquette.

Proponents of Edo shigusa say its lessons, which they believe were practiced by merchants during the period, embody the compassion and humbleness inherent among Japanese.

Such acts show "the way for diverse people in society to live in harmony," said Izumi Tsurumi, executive director of Tokyo-based nonprofit group Edo Shigusa.