The title is something of a trompe l'oeil -- Walker, first the curator, then the director of Washington's National Gallery since its inception -- reveals very little of himself and is always modest and courteous in this guided tour of his life as an intermediary -- ""collecting collectors who would. . . become donors."" After Harvard, Walker spent three of his best and happiest years in the tutelage of Berenson in his beautiful sanctuary, I Tatti -- then as a still very young man assisted Mellon with his new gallery. His book rarely deals in the covert, avid scuffle for great works although his purchase of Leonardo's inaccessible Ginevra de Benci, from Liechtenstein, took a persistent sixteen years. Mostly he discusses men of great wealth who were able to vicariously achieve immortality through their acquisitions and later benevolences: two generations of Mellons; the Kress brothers; the tenacious Chester Dale guided by the taste of his wife; bargain hunter-entrepreneur ArmandHammer who liked to buy but then give away; Walker's close friends the Wrightsmans who he claims have the ""finest collection"" in the US. Walker teaches and chides from experience: collect contemporaries when you are young; beware of fashion (and the Impressionists); buy only what you genuinely love, although the collector inevitably becomes insatiable. And additional caveats for museums in an expansionist era. . . . All of which is to say that with genuine luster rather than the hustling chutzpah and razzle-dazzle of Duveen, Walker quietly ministered to the higher interests of art, artists and proud possessors.