There are few philosophers who have been so influential in their lifetime and had so much influence, only to be subsequently ignored, as Henri Bergson (1859-1941). When in April, 1922 Bergson debated Einstein on the nature of time, it was Bergson who was far better known and respected. Now Einstein's achievements are known to everyone, but very few people outside philosophy departments have even heard of Bergson. In the wake of Friedrich Schelling and those he influenced, Bergson targeted the Cartesian dualism which permeates the culture of modernity. In doing so, he challenged deep assumptions rooted in and cemented in place by Descartes' philosophy. It this article I will argue that Bergson made considerable progress in this attack on Cartesian dualism, and diverse philosophers subsequently built on his ideas. However, failure to appreciate the source of these ideas has weakened their force, scattering them among diverse philosophers and scientists and their disciples who drew upon Bergson's work while forgetting details of his philosophy. This article is an effort to rectify this situation.