Augustine and Anselm form a common tradition in mediæval thought about angelic sin, a tradition rooted in patristic thought and centred on their attempts to give a philosophically coherent account of moral choice. Augustine concentrates on the reasons and causes of angelic sin, especially in reference to free will; Anselm adopts Augustine’s analysis and extends it to issues about the rationality of sinful choice. Each takes Lucifer’s primal sin to be the paradigm case. Lucifer, undistracted by bodily desires and unencumbered (...) by history, committed the first moral misdeed in an entirely good universe newly created by an entirely good God. The challenge is to give a philosophical account that permits us to understand how the best and brightest of all angels nevertheless made a sinful choice in such uniformly positive circumstances. (shrink)