Philosophy 101 Subject is a course that covers the works of two of the most influential philosophers in history, Plato and Kant. Plato was a classical Greek philosopher who wrote extensively on the nature of reality, knowledge, and justice. His most famous work is The Republic. Immanuel Kant was a German philosopher who wrote on topics such as morality, freedom, and the limits of human understanding. His most famous work is Critique of Pure Reason.