Editor-in-chief Horowitz (Occidental College), who contracted for the project in August 2002, acknowledges the remarkable efficiency and expertise of all involved to have thoughtfully prepared this six- volume reference in a few years rather than a decade or more. This is an all-new work though it draws inspiration from the landmark Dictionary of the History of Ideas; Studies of Selected Pivotal Ideas (edited by Philip P. Wiener), published in 1973-4, by Charles Scribner's Sons (which is now available gratis online). The earlier work was published at a time when interdisciplinarity was a new trend; and the new work continues this emphasis, as stated in the preface, by "its focus on the most influential multidisciplinary practices, such as 'Mysticism,' 'Mathematics,' and 'Reading,' which have ancient origins, and 'Representation: Mental Representation' and 'Bioethics,' which are creations of our own times." The approximately 600 articles are signed, include references and cross-references, and are arranged chronologically. Access is facilitated by a theme-oriented Reader's Guide (in each volume) and a substantial index, which occupies about half of volume six. Some b&w photos and boxed sidebars are included but do not play a major role.