If Coolidge were alive, he would see no reason to say this much about himself. Sobel (Dangerous Dreamers, 1993, etc.) is a man on a mission. He considers the conventional wisdom on Calvin Coolidge—that he was a naive simpleton manipulated by political bosses, servant of business and the rich, a do-nothing president whose inactivity set the stage for the Depression--unfair trivialization that reflects the failure of American historians to take Coolidge seriously. His revisionist effort confronts two problems, however. First, Coolidge had his personal papers destroyed, leaving very little documentary basis on which to write a biography. Sobel notes that “Coolidge . . . kept his cards close to his vest, and we know little about what he knew or thought.” Nevertheless, a lack of evidence doesn—t deter Sobel, who relies extensively on the ex-president’s slim autobiography and his own ability to make confident assertions when confronted with matters requiring interpretation. Second, the contemporaneous put-downs of Coolidge are not only much more colorful and memorable than anything that can be extracted from “silent Cal,” they are compelling as well. This imposes a need for heavy mental gymnastics if Sobel is to support his thesis. Consider a statement by Walter Lippmann quoted by Sobel in response to the charge that Coolidge slept away his time in the White House: “Inactivity is a political philosophy and a party program with Mr. Coolidge, and nobody should mistake his unflinching adherence to it for a soft and easy desire to let things slide.” Sobel sidesteps the sarcasm, concluding that “This is quite different from sleeping away five years in office.” Resting one’s case on a distinction between doing nothing for lack of a purpose and doing nothing on purpose illustrates the daunting nature of Sobel’s task, as well as raising concerns about why he is actually pursuing it. Most readers will find it difficult to stifle a yawn.