This new, comprehensive study of Leibniz’s system of thought reveals a philosopher equally intrigued by the complexity of physical reality and the fascinations of his metaphysical laboratory. Many of his most important, but never previously published papers are evaluated in this book.Too often put down as an arch-metaphysician, Leibniz is seen in these pages as a venturer of breathtaking boldness, his ambition being nothing less than to actually solve the enigma of existence. Accordingly his system embraced science equally with metaphysics; they complement and pollinate each other.The outcome is a view of his system as a double ontology. Reality is the domain of the actual; metaphysics the laboratory of the possible. Metaphysics springs to life with his scintillating detective work on force, motion, time, space, limits, infinity, folds, fractals and many other issues that are ‘hot’ again today; while in all these a direct line is kept open to their impact on physical existents and our understanding of reality.This book is equally suited to expert Leibnizians as to students of Early Modern philosophy; and it may be read with profit by anyone interested in this thinker, whom Bertrand Russell called “one of the supreme intellects of all time”.