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 meta...