With the publication this month of the critical edition of George Santayana’s (1863–1952) Reason in Science, Book 5 of The Life of Reason by The MIT Press, the Santayana Edition has completed Volume VII of The Works of George Santayana. Five years after the first book of this volume appeared, Reason in Science becomes the 19th of 34 books projected to be published in 20 volumes of The Works of George Santayana. The five books of The Life of ReasonReason in Common Sense, Reason in Society, Reason in Religion, Reason in Art, and Reason in Science—were originally published in 1905–06, are seminal texts in American philosophical naturalism. In this work Santayana acknowledges the natural material basis of human life while tracing the development of the human capacity for appreciating and cultivating ideals.