erving as both an introduction and an explanation, this book seems the sort that librarians working with young people are always on the lookout for. The author is a professor of philosophy at Yale University and his discussion of 15 Greek philosophers indicates the sort of teacher who can invest an exact and demanding subject with fascination. Short chapter headings set these philosophers -- from Thales to Aristotle -- in the context of their times and highlight their philosophical breakthroughs. Each philosopher's work and its meaning is defined and discussed in terms of its ultimate impact on the world of ideas. The special features of this book is the emphasis place on the comparisons and contrasts, as well as the contributions, of the ancient thinkers to contemporary thought. Appendices. Bibliography. Charts. Tables. Index. Seen without the planned photographs.