Book excerpt: Science is a living, organic activity, the meaning and understanding of which have evolved incrementally over human history. This book, the second in a roughly chronological series, explores the evolution of science from the advents of Christianity and Islam through the Middle Ages, focusing especially on the historical relationship between science and religion. Specific topics include technological innovations during the Middle Ages; Islamic science; the Crusades; Gothic cathedrals; and the founding of Western universities. Close attention is given to such figures as Paul the Apostle, Hippolytus, Lactantius, Cyril of Alexandria, Hypatia, Cosmas Indicopleustes, and the Prophet Mohammed.