Contemporary historians examining moral theology in the Middle Ages question whether the practice of proscribing certain kinds of human acts as intrinsic moral evils has a legitimate basis in the Christian ethical tradition. John Dedek argues that this proscription does not fully emerge until the work of the fourteenth-century thinker Durandus of St. Pourçain. Dedek’s historical focus, however, is upon theological discussions which consider God’s absolute power and his ability to dispense from or command any human act whatsoever. The focus (...) for addressing this question should be instead to examine how medieval thinkers understand the structural elements of a human act, especially in response to the ethical intentionalism promoted by the twelfth-century thinker Peter Abelard. An examination of Peter Lombard’s response to Abelard reveals that certain human acts were proscribed as intrinsic moral evils long prior to Durandus, and that Augustine serves as a source for this doctrine. (shrink)