Immanuel Kant was a German philosopher and is often referred to as one of the most influential thinkers in modern history. He is best known for his work in the fields of metaphysics, epistemology, ethics, and aesthetics. Kant's major work, the Critique of Pure Reason, is considered to be one of the most important works in the history of philosophy. Kant's influence on Western philosophy is immense, and his ideas have been widely discussed and debated by philosophers throughout the centuries.