 Lange’s influence on nineteenth and twentieth century thought included, but was not limited to, his influence on the nascent Marburg school of neo-Kantianism (in this respect, see Sieg 1994, Köhnke 1991, Holzhey 1986). His engagement with Darwinism, materialism, socialism, and Marxism contributed to his “unusually strong” presence in the “intellectual climate of the final quarter of the nineteenth century” in Germany (Jacobsen 1999, 7). Max Weber, the philosopher and pedagogist Friedrich Paulsen, and others were influenced by Lange’s work (Jacobsen 1999, see also Braun 1881, Freimuth 1995). In fact, “Friedrich Paulsen, Paul Natorp, and Hans Vaihinger, all describe their reading of Lange as a conversion experience leading them into philosophy” (Hill 2003, Köhnke 1991, 211–213).