Philosophy does not contribute to our knowledge of the world we live in after the manner of any of the natural sciences. You can ask any scientist to show you the achievements of science over the past millennium, and they have much to show: libraries full of well-established facts and well-confirmed theories. If you ask a philosopher to produce a handbook of well-established and unchallengeable philosophical truths, there’s nothing to show. I think that is because philosophy is not a quest for knowledge about the world, but rather a quest for understanding the conceptual scheme in terms of which we conceive of the knowledge we achieve about the world. One of the rewards of doing philosophy is a clearer understanding of the way we think about ourselves and about the world we live in, not fresh facts about reality.