 Sidgwick may have thought that the “deepest problems” of human life had to do with the religious and ethical problems that inspired his parapsychological research, but he nonetheless also devoted an enormous amount of time and energy to both the theoretical and practical sides of economics, politics, law, and ethics, which were after all relevant to the problem of the dualism. In this he was certainly in line with the tradition of Bentham and James and J. S. Mill, all of whom presented utilitarianism as a comprehensive doctrine that prioritized political, legal, and economic reform (Albee 1901; Skorupski 1993; and Rawls [1993], 1996, 2007). If Sidgwick had his own take on these subjects, his perspective was still that of a theorist and reformer with broad “interdisciplinary” concerns, rather than that of an ethicist obsessed with personal ethics narrowly construed. His professional credentials as both an economist and political scientist were impeccable, although the professional organizations now associated with these disciplines were only beginning to take shape in his era. He was an active member of the section of the British Association concerned with political economy and economics, and his book on The Elements of Politics, first published in 1891, became a staple of political science at Cambridge and elsewhere. He is best thought of as one of the founding fathers of the “Cambridge School” of economics, one whose contributions should be classed with those of Alfred Marshall and A. C. Pigou (Backhouse 2006; Medema 2009; Cook 2009; Winch 2009; and Cord 2017). 