The Thomist: A Speculative Quarterly Review

AQUINAS'S ACCOUNT OF DOUBLE EFFECT* THOMAS A. CAVANAUGH University ofSan Francisco San Francisco, California DOUBLE-EFFECT REASONING (DER)-often called the "principle," "rule," or "doctrine" of double effect-is often, if not always, attributed to Thomas Aquinas tout court.' Yet, I will argue, Thomas's account substantially differs from contemporary double-effect reasoning (DER) insofar as Thomas considers the ethical status of risking an assailant's life while contemporary accounts of DER focus on actions causing harm foreseen as inevitable.2 Of course, if DER applies to cases in which harm is foreseen as an inevitable result of an otherwise good action, it will apply * I thank Professor Ralph Mcinerny for the opportunity to present an earlier version of this paper at the Second Annual Thomistic Conference at the University of Notre Dame. I thank Professor Raymond Dennehy for the chance to read a portion of this paper before the American Maritain Association's 1995 meeting in San Francisco, California. Finally, I thank Professor Michael Torre for his insightful criticims and close reading of this paper from which it and I profited greatly. 1 The standard article on the history of DER is Joseph Mangan's "An Historical Analysis of the Principle of Double Effect," Theological Studies 10 (1949): 41-61. J. Ghoos differs with Mangan over exactly where in Aquinas's work the sources of DER can be found: ]. Ghoos, "L'Acte a Double Effet: Etude de Theologie Positive," Ephemerides Theologicae Lovanienses 27(1951): 30-52. In fact, what Ghoos notes, although not explicitly , is the conflation by Thomas's interpreters of two distinct strands in Aquinas's work: the indirect voluntary of Summa Theologiae 1-11, q. 6, a. 3 and double effect of STh 11-11, q. 64, a. 7. For a more recent consideration of the history of DER see L.1. Ugorji, The Principle ofDouble Effect: A Critical Appraisal ofIts 1raditional Understanding and Its Modern Reinterpretation (Frankfurt am Main: Peter Lang, 1985). 2 See Jeff McMahan, "Revising the Doctrine of Double Effect," Journal of Applied Philosophy 11 (1994): 201-12; Warren Quinn, "Actions, Intentions, and Consequences: The Doctrine of Double Effect," Philosophy and Public Affairs 18 (1989): 334-51; and Joseph Boyle, "Toward Understanding the Principle of Double Effect," Ethics 90 (1980): 527-38. 107 108 THOMAS A. CAVANAUGH to cases in which harm is foreseen as being a possible result. The reverse, however, need not obtain. For example, one might think that it is ethical for an ironworker knowingly to risk his life doing dangerous work while one would not think it ethical for the ironworker knowingly to do work from which his death would follow inevitably. Thus, one might think that it is ethical to risk causing harm that one would not think it ethical to cause inevitably. I will argue that Aquinas holds something like this in his account of DER l. QUESTION 64, ARTICLE 7, AND PRAETER INTENTIONEM The locus classicus of double-effect reasoning is Aquinas's discussion of homicidal self-defense in STh II-II, q. 64, a. 7.3 Question 64 occurs within Aquinas's consideration of vices opposed to commutative justice. It concerns what Aquinas considers the greatest injury committed upon one's neighbor against his will: his death. In article 7, Thomas asks whether it is licit to kill a man in self-defense. He offers a number of objections, two of which are voiced by St. Augustine. The first comes from his epistle to Publicola; the second Thomas takes from De libero arbitrio. In the latter Augustine asks, "How are they free from sin in the sight of divine providence who, for the sake of these contemnible things, have taken a human life?" (obj. 2). Aquinas notes that among the slight goods that men may forfeit against their wills, Augustine includes corporeal life. Augustine appears to rule out homicidal self-defense. Aquinas interprets Augustine as not permitting the intentional taking of an aggressor's life. He has noted earlier in his discussion of war (STh II-II, q. 40, a. 1) that Augustine thinks it licit for one charged with the public good to take life during a war. Accordingly, Aquinas considers the bailiff...