The Elements of Newton's Philosophy. By Voltaire. (Guildford and London: Billing and Sons Ltd., 1967. Pp xvi, 363.) In this essay, published in 1738, Voltaire explains the philosophies not only of Newton, but largely of Descartes because of his contributions to the fields of geometry. In Voltaire's concise explanation of the paradigms of Newton and other philosophers related to the fields of astronomy and physics, Voltaire employs geometry through diagrams and images and proves his claims with calculus. In fact, Voltaire states that this essay is for people who have the desire to teach themselves, and makes the intent of the book a textbook. In 25 chapters, and each part of 357 pages, plus six pages of definitions, Voltaire explains Newton's discoveries in the field of optics, the spectrum and colors of the rainbow, musical notes, the Laws of Attraction, refuting the Descartes' philosophy of the cause of gravity and the structure of light and demonstrating Newton's new paradigm, or Philosophy as Voltaire would call it. Voltaire in a sense created the idea that Newton's principles were a new philosophy and recognized the possibility of errors. Through mathematical problems and solutions Voltaire shatters the paradigm of every faithful observer of Descartes' philosophy and calls his way of thinking "Chaos" (p. 8). What amazed me was their ability to calculate things they had never been able to do before, such as the speed of light, showing that it takes only eight minutes for one or more rays of light from the Sun to reach the Earth. Through Newton's achievements in calculus and his use of geometry, Voltaire showed how we can estimate the distance between the Earth and the stars and planets. Voltaire accurately calculates the time it takes the Sun to rotate as 25 and a half days, which is an accepted answer today due to the variance moving poleward. It was sometimes difficult to understand the principles of this book when reading calculus, but with the inclusion of geometry the material becomes accessible to more educated readers. Because it has the appearance of a textbook to spread understanding of the new philosophy, this book should be recommended to anyone studying the history of science, philosophy, or any of the various influential philosophers who have contributed to understanding and truth through experimentation. I was amazed at the similarities between the English published in the late 1730s and that of today. The only real differences are some capitalization that we don't follow, the use of an altered-looking lowercase f, which is pronounced with the s sound, and some European spelling.