We live in an age of mass persuasion. Leaders and institutions of every kind - public and private, large and small - must compete in a rowdy marketplace of images and messages seeming to come at us from all directions - in print, on radio and television, and on the Web.

It wasn't always so. In the early and middle 20th century, a handful of creative geniuses in advertising and public relations - J. Walter Thompson, Edward Bernays, David Ogilvy, Ray Rubicam, and others - launched their once-sleepy industries into the very center of American life. And most of them point to one individual as the man who started it all: Albert D. Lasker.

But Lasker - who resolutely hid from the spotlight - has remained an enigma. Now, Jeffrey Cruikshank and Arthur Schultz, drawing on a treasure trove of previously unknown papers, have written a fascinating biography of one of the 20th century's most intriguing figures.

Lasker helped invent "reason why" advertising, market research based on direct-mail advertising, premium coupons, and a host of other industry innovations. He invented and promoted powerful brands that are still with us today: Sunkist and Sun-Maid, Kotex and Kleenex, Puffed Wheat and Puffed Rice, and many others.

But his impact went far beyond traditional advertising. Lasker was a crusader against anti-Semitism. A public-relations master, he engineered Warren G. Harding's presidential campaign, and designed the strategy that ended Upton Sinclair's bid for governor of California. And the Lasker Awards, for contributions to medical science, are sometimes referred to as "America's Nobels."