An important figure in the development of panpsychist thought is Arthur Schopenhauer (1788–1860). Schopenhauer was influenced by Kant’s view that we lack an understanding of reality as it is in and of itself, but he made a crucial exception for the immediate knowledge one has of oneself. Taking will to be the fundamental quality one is aware of in introspection, Schopenhauer thus theorised that will is the inner nature of all things. This line of reasoning bears a striking similarity to, and indeed is an important influence on, the contemporary Russellian monists, whom we will discuss below.