The impact of the work of German mathematician GOTTFRIED WILHELM LEIBNIZ (1646-1716) on modern science and technology is all but incalculable. His notation for infinitesimal calculus-which he developed independently of Newton-remains in use today, and his invention of binary counting is the basis for modern computing. He was a powerfully influential philosopher as well, and is still considered, alongside Descartes and Spinoza, one of the great 17th-century rationalists. Because much of Leibniz's thinking in the realm of the sciences flowed from his philosophy, understanding how he approached the natural world and humanity's place in it is vital to understanding his contributions to modern science. This edition collects two of Leibniz's foundational works, "Discourse on Metaphysics" and "The Monadology," which expound on concepts of philosophical "optimism"-that we live in the best of all possible worlds-and consequently features Leibniz's thoughts on the nature of physical matter. This classic work will intrigue all students of science and philosophy.