As British and American idealism waned, new realisms displaced them. The common background of these new realisms emphasized the problem of the external world and the mind-body problem, as bequeathed by Reid, Hamilton, and Mill. During this same period, academics on both sides of the Atlantic recognized that the natural sciences were making great strides. Responses varied. In the United States, philosophical response focused particularly on functional psychology and Darwinian adaptedness. This article examines differing versions of that response in William (...) James and Roy Wood Sellars. James viewed the mind as a “fighter for ends.” His neutral monism, by taming the mind-body problem and the problem of the external world, provided a secure metaphysics of mind as functional activity. In contrast, Sellars ’s scientific realism endorsed physical reality but was not mechanistic or reductionist. His critical realism and evolutionary naturalism offered novel metaphysical and epistemological positions in comparison with other American and British realisms. James and Sellars are distinguished from British philosophy in 1890–1918 in the types of realism they endorsed and in their success at introducing Darwinian evolutionary considerations and functional psychology into mainstream philosophy. (shrink)