If we accept Wittgenstein's word for it, he is the last philosopher. In his view, philosophy in the traditional sense was finished. Ludwig Wittgenstein was a superb logician who distrusted language and sought to solve the problems of philosophy by reducing them to logic. All else—metaphysics...

With Friedrich Nietzsche, philosophy was dangerous not only for philosophers but for everyone. Nietzsche ultimately went mad, but his ideas presaged a collective madness that had horrific consequences in Europe in the early 1900s. Though his philosophy is more one of aphorisms and insights than...

Just a century after it had begun, philosophy entered its greatest age with the appearance of Socrates, who spent so much of his time talking about philosophy on the streets of Athens that he never got around to writing anything down. His method of aggressive questioning, called dialectic, was...

During his lifetime, Jean-Paul Sartre enjoyed unprecedented popularity for a philosopher, due partly to his role as a spokesman for existentialism—at the opportune moment when this set of ideas filled the spiritual gap left amidst the ruins of World War II. Existentialism was a philosophy of...

In an age when philosophers had scarcely glimpsed the horizons of the mind, a boy named Aristocles decided to forgo his ambitions as a wrestler. Adopting the nickname Plato, he embarked instead on a life in philosophy. In 387 BC he founded the Academy, the world's first university, and taught...