Immanuel Kant was a German philosopher from the Enlightenment era. His biggest contributions to philosophy are in epistemology and ethics, through his books, A Critique of Pure Reason, and Groundings on the Metaphysics of Morals. He famously resolved the debate between rationalism and empiricism, and offered a vehement defense of his ethical school of thought, known as deontology. Kant is often used in LD Debate, so it's extremely useful to be familiar with his thoughts and treatises.