This essay argues that Aquinas's position regarding the killing of innocent people differs significantly from other representatives of the Christian just war tradition. While his predecessors, notably Augustine, as well as his successors, from Cajetan and Vitoria onward, affirm the legitimacy of causing the death of innocents in a just war in cases of necessity, Aquinas holds that causing the death of innocents in a foreseeable manner, whether intentionally or indirectly, is never justified. Even an otherwise legitimate act of just war cannot legitimate causing the death of innocent people, as this can never advance the common good. This stance also contrasts sharply with much modern and contemporary double effect theorizing in relation to jus in bello. In this regard, Aquinas's position, shaped decisively by his biblical and theological commitments, may point the way towards an ethical orientation beyond the typical divisions of “pacifism” and “just war.”