ABSTRACT
Medieval voluntarists claim that the will is a free power that can always reject an intellectual judgement, even if it is the best possible judgement in a given situation. But does this not lead to irrationalism? A will that dismisses the best judgement without replacing it with another judgement seems to be a power that acts without any rational ground. This chapter examines this problem by analysing a controversy in the late thirteenth century. It first looks at Siger of Brabant, who defends a form of determinism according to which the will is acted upon by the intellect as an efficient cause and so necessarily accepts the intellect’s judgement. It then discusses Henry of Ghent’s anti-determinism: Since the intellect is nothing but an occasional cause, it cannot act upon the will and force it to accept a judgement. This idea of occasional causation, rather than irrationalism, provides the basis for Henry’s claim that the will is a free power. Nevertheless, his reaction to Siger shows that there is a deep disagreement about the scope of explanation. On Henry’s view, the will’s activity is not fully intelligible because it cannot be fully explained by reference to intellectual judgements. Voluntarism, therefore, breaks with rationalism by rejecting the Principle of Sufficient Reason, as the chapter argues in the final section.
