 Lange’s History of Materialism is known to have had an influence on Friedrich Nietzsche, who learned about Gustav Fechner and others in the “psychophysics” movement from Lange’s work. Nietzsche went on to re-define philosophy as “psycho-physiology” in Beyond Good and Evil (Nietzsche 2002/1886, 23, see also Gori 2015a). George L. Stack’s Lange and Nietzsche brought the question of Lange’s influence on Nietzsche to the forefront. For critical responses see Breazeale (1989), Seigfried (1989), Wilcox (1989), and Pletsch (1991); also see Salaquarda (1978, 1979, and 1996), Leiter (2013), Campioni (2019); Swift (2005). Stack responds to critics in Stack (1989 and 1991). R. Kevin Hill assesses the influence of Lange, Schopenhauer, and Kant on Nietzsche’s thought (2003); for a critical perspective see Clark and Dudrick (2005). Villarroel Soto et al. (2020) and Slama (2019) assess the extent to which Nietzsche can be considered a Kantian, and how Lange may have influenced Nietzsche in this direction.