Contains an edition of several hitherto unpublished manuscripts in Leibniz's hand illustrating his first reading of, and reaction to, Newton's "Principia Mathematica". Meli examines the important implications of this new material on our views about mathematics in the 17th century.

Leibniz's dispute with Newton over the physico-mathematical theories expounded in the "Principia Mathematica" (1687) have long been identified as a crucial episode in the history of science. Bertoloni Meli examines several hitherto unpublished manuscripts in Leibniz's hand, illustrating his first reading of and reaction to Newton's "Principia". Six of the most important manuscripts are here edited for the first time. Contrary to Leibniz's own claims, this new evidence shows that he had studied Newton's masterpiece before publishing "An Essay on the Causes of Celestial Motions". This article, representing his response to Newton, is included here in English translation. Meli analyzes the important implications of this episode on a variety of themes ranging from priority claims to the mathematization of nature in the 17th century. Besides providing a careful study of Leibniz's style and strategy, the author examines how our perception of Newton's achievement is affected and the reception of the rival theories by the mathematical community around 1700.