The concept of moral and natural ability has long been a contested distinction within Reformed theological anthropology. As Charles Hodge would claim, “The distinction between natural and moral ability, as commonly made, is unscriptural.” However, other Reformed theologians, most notably Jonathan Edwards, made much of this distinction in their articulation of theological anthropology. Andrew Fuller would rely on Edwards to introduce this distinction to solve the theological issues associated with hyper-Calvinism among eighteenth-century English Baptists. This paper will argue that Fuller was correct in his assertion that the distinction between moral and natural ability had been well attested within the Reformed tradition, notably within the writings of John Owen and John Calvin. Implications for contemporary theological anthropology will be drawn out.