In this collection, first published in 1951, the central theme is that everything has a history, and that we cannot fully understand anything without some knowledge of its history. Professor Haldane writes mainly on geology, astronomy and zoology, but includes a variety of other topics, including eugenics, Einstein, and C. S. Lewis. His outlines of zoology, of the geology of England, and of the evidence for astronomical theories, will be of great use to students and teachers.