"The approach to philosophy that I favor, attempting to answer fundamental questions by relating them to scientific findings, is called naturalism. Many philosophers since Plato have scorned naturalism, arguing that science cannot provide answers to the deepest philosophical questions, especially ones that concern not just how the world is but how it ought to be. They think that philosophy should reach conclusions that are true a priori, which means that they are prior to sensory experiences and can be gained by reason alone. Unfortunately, despite thousands of years of trying, no one has managed to find any undisputed a priori truths. The absence of generally accepted a priori principles shows that the distinguished Platonic philosophical tradition of looking for them has failed. Wisdom must be sought more modestly. Sometimes, however, philosophy gets too modest. The highly influential Austrian/British philosopher Wittgenstein asserted that philosophy is unlike science in that all it should aim for is conceptual clarification. In his early writings, he looked to formal logic to provide the appropriate tools, and in his later work he emphasized attention to ordinary language. He claimed that philosophy “leaves everything as it is.” Much of twentieth-century philosophy in English devoted itself to the modest goal of merely clarifying existing concepts. But no one has learned much from analyzing the logic or the ordinary use of the words “wise” and “wisdom.” We need a theory of wisdom that can tell us what is important and why it is important. Such theorizing requires introducing new concepts and rejecting or modifying old ones."