"I think, therefore I am," French philosopher René Descartes wrote in a 1637 discourse. The statement is a short-and-sweet summation of philosophy: the study of the mysteries of knowledge, thought, existence and reality.
Philosophy, translated from the Greek, means "love of wisdom." We've all likely heard of Plato, Aristotle and Socrates, the classical Greek philosophers, but though the Greeks gave a name to the field of study, it dates back to ancient Egyptian and Chinese cultures.
Though few people in the modern world ever make a living as a so-called philosopher, the study of philosophy is immense and the subject is examined from all angles at great universities around the world.
OpenCulture.com has compiled a list of over 130 free philosophy courses that you can download, both audio and video, from some of the best institutes of higher education on the planet. Courses from Harvard, Duke, Notre Dame, MIT, Yale, Oxford and many more are included.
Just about any philosophical topic you could imagine is covered by these courses. There are courses on individual philosophers like those mentioned above, as well as Machiavelli, Nietzsche, Proust, Kant and more. Or you can study topics like Critical Reasoning, Existentialism, Philosophy of Religion and even The Meaning of Life.
Click on a button below to explore the list. Individual courses have links to audio or videos. Note that some require iTunes.