Say a deranged woman attacked the Mona Lisa as it hung in the Louvre last week. It would be big news worldwide, including in the U.S.. Your favorite TV station would of course show the painting and discuss its historical and economic value. Now what if instead of the Louvre it was America’s National Gallery in Washington, and instead of DaVinci’s Mona Lisa it was Gaugin’s Two Tahitian Women. Same deal, right? Some perky anchorwoman would read the teleprompter: “…masterpiece done for the upcoming Exposition Universelle of 1900, similar to Gaugin’s famous works now hanging in London’s Tate and Moscow’s…