 The problem of free will was an important topic in the modern period, with all the major figures wading into it (Descartes 1641 [1988], 1644 [1988]; Hobbes 1654 [1999], 1656 [1999]; Spinoza 1677 [1992]; Malebranche 1684 [1993]; Leibniz 1686 [1991]; Locke 1690 [1975]; Hume 1740 [1978], 1748 [1975]; Edwards 1754 [1957]; Kant 1781 [1998], 1785 [1998], 1788 [2015]; Reid 1788 [1969]). After less sustained attention in the 19th Century (most notable were Schopenhauer 1841 [1999] and Nietzsche 1886 [1966]), it was widely discussed again among early twentieth century philosophers (Moore 1912; Hobart 1934; Schlick 1939; Nowell-Smith 1948, 1954; Campbell 1951; Ayer 1954; Smart 1961). The centrality of the problem of free will to the various projects of early modern philosophers can be traced to two widely, though not universally, shared assumptions. The first is that without belief in free will, there would be little reason for us to act morally. More carefully, it was widely assumed that belief in an afterlife in which a just God rewards and punishes us according to our right or wrong use of free will was key to motivating us to be moral (Russell 2008, chs. 16–17). Life before death affords us many examples in which vice is better rewarded than virtue and so without knowledge of a final judgment in the afterlife, we would have little reason to pursue virtue and justice when they depart from self-interest. And without free will there can be no final judgement.