Ludwig Wittgenstein Ludwig Wittgenstein is one of the most influential philosophers of the twentieth century, and regarded by some as the most important since Immanuel Kant . His early work was influenced by that of Arthur Schopenhauer and, especially, by his teacher Bertrand Russell and by Gottlob Frege , who became something of a friend. This work culminated in the Tractatus Logico-Philosophicus , the only philosophy book that Wittgenstein published during his lifetime. It claimed to solve all the major problems of philosophy and was held in especially high esteem by the anti-metaphysical logical positivists . The...