In 2015, science will celebrate the half-centenary of the first paper on fuzzy sets [1], which prompted a paradigm shift in the community of scientists involved in the study of machine intelligence. In preparation for the occasion, several retrospective initiatives have been undertaken to highlight the development of the science of fuzzy sets and pay tribute to the work of its father, Lotfi Zadeh. This book is the result of one such initiative.

This is the first of a two-volume set, for which a great number of authors have been invited to write very short papers (four to six pages, including bibliography). The complete collection consists of 110 papers (and four appendices), alphabetically sorted by the first authors. This volume contains 62 contributions by authors with surnames ranging from A to Ma. The appendices will be included in the second volume. Contributors include top-level scholars who have participated in the development of fuzzy logic in the past 50 years.

The title is, in some respects, misleading. While “fuzziness” is the quality of lacking sharp boundaries, the title suggests a philosophical discussion of the concept underlying fuzzy set theory and fuzzy logic. But that is not the case here, at least not completely. The papers are quite heterogeneous, ranging from personal stories of meetings with Zadeh (with photographs included) to extremely concise (and quite hermetic, due to the space limitations) reports of various research niches in fuzzy logic.

Of primary interest are the papers (quite a few, at least in this volume) that really hit the target of the title. These are not necessarily rigorously written scientific papers, but are equally thought-provoking and stimulating. As an example, “The Parable of Zoltan,” by Bezdek, is an amusing metaphorical story concerning the difference between fuzziness and randomness--very useful for explaining such subtle matters to students! On the other side of rigor, other authors give very intriguing arguments on subjects such as philosophical foundations, connections with classical logic, and relations with probability theory. It is a pity that the stringent page length constraint was applied to these papers, too; surely more space should have been devoted to these subjects.

Most of the book’s papers, however, do not deal with the philosophical aspects of fuzziness. They report lived experiences of individuals or research groups who came across some works by Zadeh or met him personally. These papers are mainly of historical interest (especially those reporting past experiences in countries involved in the Cold War with the US), but provide little information on the subject of fuzziness.

In summary, this book could be useful for readers interested in the history of science who want to understand how people, groups, and countries got involved in the research of fuzzy logic. Readers interested in philosophical aspects could find some useful material here and there, although without the pretense of an extensive discussion. On the other hand, for readers interested in mathematical or technical aspects, the discussions might be too limited to be of any use.