Volume 25, Issue 2, Autumn 2020
The Doctrine of Double Effect
A Comparison of the Version of Thomas Aquinas and Contemporary Accounts as Formulated by Joseph Mangan and Joseph Boyle
The aim of the article is to present some of the differences and similarities in various versions of the double effect principle (DDE or PDE). The following formulations will be analyzed: that of Thomas Aquinas and two contemporary approaches, namely those of Mangan and Boyle. It will be shown that the presented modern versions vary significantly and the distinction between their intended and only predicted effects is far from clear. As a result, the different contemporary formulations of DDE lead to contradictory conclusions, with some justifying what others condemn. Moreover, it will be demonstrated that, unlike Aquinas, contemporary authors mostly concentrate on unintentionality condition while neglecting the proportionality requirement. So, unlike Aquinas, they only take into account a narrow scope of cases, where the evil effect occurs with certainty, which leads to a complicated and intricate hypothetical intention test like Donagan’s. It will be shown that, besides its theoretical indistinctness, DDE lead to serious pragmatic risks. It can be quite easily misused as a kind of psychological mechanism to protect self-esteem from a sense of guilt since wrong-doing is treated as merely a predicted unintended effect.