 One could find views that resemble Russellian monism in certain respects throughout the history of philosophy. For example, panpsychism is very old indeed (and not distinctive to the west). But it is hard to find views approximating full-fledged Russellian monism before the early modern period. This is not a coincidence: the theory is closely tied to modern physics, which was first developed during that era. Yet it did not take long for the theory, or something akin to it, to emerge. Arguably, Russellian monism can be ascribed to various early modern figures, including at least Gottfried Wilhelm Leibniz, Immanuel Kant, and Arthur Schopenhauer.