 Peter Lombard’s role in the evolution of the concept of conscience is both surprising and unsurprising. It is—at first sight, anyway—surprising because Lombard does not discuss conscience or synderesis in any actual detail. Indeed, he does not, strictly speaking, mention the terms “synderesis” or “conscience” at all. What he does is merely to allude to Jerome’s commentary on Ezekiel in the context of discussing the will’s role in how rational agents can naturally want what is good while simultaneously being slaves to sin (Peter Lombard, Sententiae in IV libros distinctae, 2.39; Potts 1980: 92). In St. Paul’s reference to moral weakness in Romans 7:15, he famously says: “For I do not do what I want but do what I do not want”. Is Paul suggesting, asks Lombard, that we have two separate wills: one naturally oriented towards the good and another oriented towards sin? Or is it rather the case that we have a single will that, although naturally inclined to the good, contains a defect which also “takes pleasure in what is evil” (Sententiae in IV libros distinctae, 2.39; Potts 1980: 93)? Amongst those who hold the first view, the motivating power that orients us towards the good is called the “natural” will, while the inclination towards sin resulting from the Fall is called “free will” (or “free choice”). With respect to the former, Peter writes: