  Adickes (1924), Harman (1982), Friedman (1992), Laywine (1993), Schönfeld (2000), Kuehn (2001), Lefevre &amp; Wunderlich (2000), and Watkins (1997, 2001, 2003, 2006, 2013) have emphasized the importance of scientific issues in the development of Kant's thought during his pre-Critical period, as he reacted to Leibniz, Newton and other, more immediate predecessors (such as Christian Wolff, Christian August Crusius, Leonard Euler, Pierre Louis Moreau de Maupertuis, and Martin Knutzen). Smith (2013) reconstructs Kant's picture of matter in the Physical Monadology. 