The German polymath Gottfried Wilhelm Leibniz made significant contributions to philosophy, logic, mathematics, physics, jurisprudence, politics, the mechanical arts, and history. He worked as a diplomat, an engineer, an attorney, and a political advisor. He corresponded with queens and emperors and with the most eminent intellectuals of the age. Yet his reputation as a philosopher depends largely on texts that were unpublished at the time of his death, including some never intended for publication. Besides well-known works such as the Discourse on Metaphysics, First Truths, New Essays, and Monadology, there are thousands of pages of other texts, many of which are still unpublished. Interpreting these vast writings is a daunting task, best approached by attending closely to the historical and cultural context in which he was working and by taking into consideration as many texts as possible. Against the background of Leibniz's...