Although there is nothing problematic in principle about attributing a will to human beings (§8.1), Aquinas makes considerable trouble for himself by insisting that the will is a strictly rational appetite – that in some sense it never goes against reason (§8.2). This leaves Aquinas with the need to explain the obvious and familiar fact that people are sometimes overcome by temptation, even when they apparently know better (§8.3). His account of weakness of will derives much of its plausibility from his insistence that human reasoning is not confined solely to the mind, but relies crucially on the internal senses of the brain, especially imagination and the cogitative power (§8.4). The passions, which influence our choices through these internal senses, can be controlled with difficulty and must be controlled, if we are to lead a virtuous life. But this does not mean that a virtuous person can (or should) live without emotion (§8.5).

Is the will a myth?

The previous chapter took for granted that Aquinas is entitled to the notion of a will, a separate faculty of the soul through which we form desires for the things that reason perceives to be good. It is common enough in modern philosophy to talk about free will while holding onto grave doubts about the propriety of talking about will. The locus classicus for such doubts is Gilbert Ryle (1949), who rails against the trinitarian dogma of a Mind or Soul composed of three parts, Thought, Feeling, and Will.