Nowadays we think about almost everything in numerical terms, but this engaging essay shows that this mindset developed only gradually. Cohen, a historian of science (the book is published posthumously), explores the colonization of the modern mind by numbers, beginning with the scientific revolution of the 17th century, which formulated the laws of nature as mathematical relationships and applied numerical tests to validate them, and ending with Florence Nightingale's harnessing of her "passion for statistics" to sanitation reform in the 19th century. In between, he chronicles the application of numbers to everything from medicine to demographics and the growing penchant of governments for collecting statistics and using them to guide policy. Quantification spilled over into far-flung fields; one Enlightenment philosophe reduced ethics to an algebraic equation, and a statistician analyzed the quality of plays by the age of the playwright. The spread of statistics, Cohen shows, undermined belief in free will, fingered impersonal social conditions rather than individual agency for previously moralized phenomena like crime and introduced the all-powerful figure of the "average man" to social thought; the numerical elevation of "head" over "heart" inspired a backlash from critics like Dickens, whose Hard Times is a manifesto against the statistical way of life. Full of intriguing observations, this well-written, accessible study diagrams intellectual debates that continue to dominate the modern era. Photos. (Mar.) Copyright 2005 Reed Business Information.