New Delhi, June 28 -- WASHINGTON - The man who taught Kevin Warsh what it means to run the Federal Reserve died last week, and the timing was almost too pointed to be accidental. Alan Greenspan, who steered the central bank through the 1990s technology boom without raising rates to choke it off, died on June 22 at the age of 100, leaving behind a legacy that is now a direct instruction manual, and a warning, for his self-declared successor.

Warsh invoked Greenspan by name at his own swearing-in ceremony in the East Room last month. "Chairman Greenspan was the first to tell me and show me what this role demands," Warsh said. The tribute was personal. It was also a policy statement. Warsh has argued throughout his career and his confirmati...