The book is an introductory exposition of the development of the physical and astronomical notions of the universe. It covers the period from Greek antiquity to the Copernican revolution and the Renaissance, half of the text being devoted to medieval science within both the Aristotelian and the Archimedean traditions. The book is intended for a general audience interested in intellectual and scientific developments, but should also be useful as a guide to further studies. Thus it has an extensive bibliography classifying much of the secondary literature on the subject, and also a sixty page 'dictionary' of all the scientists and philosophers mentioned in the text. This contains references to printed editions of the sources and to a selection of books and periodicals.