This book was first published in 1991. The study of ancient science and its relations with Greek philosophy has made a significant and growing contribution to our understanding of ancient thought and civilisation. This collection of articles on Greek science contains fifteen of the most important papers published by G. E. R. Lloyd in this area since 1961, together with three newer articles. The topics range over all areas and periods of Greek science, from the earliest Presocratic philosophers to Ptolemy and Galen. In each case the article is preceded by an introduction that assesses scholarly debate on the topic since the original publication. Professor Lloyd also suggests modifications and developments to his own position in the light of those debates and his own further research.