Gottfried Wilhelm Leibniz is an influential philosopher and writer particularly known for his works discussing the role of reason in human affairs. He contributed to various fields, including mathematics, metaphysics, and logic, advocating for the idea that rational thought could lead to a better understanding of the universe. His concept of monads suggests that the universe comprises individual, independent entities that reflect the whole. Leibniz's emphasis on reason as a path to knowledge profoundly influenced Enlightenment thinkers and laid foundational principles for modern philosophy.