Abstract
Summary: The importance of practical moral principles in practical moral reasoning and in moral theology tradition. The principle of double effect: its genesis and structure; from “paradigmatic” cases of casuistry to its formulation. Analysis of the formulation and argumentation based on J.-P. Gury. Its application in solving some cases. Open problems: “The proportionately serious reason” to act, the doer’s intention and freedom.
Parole chiave: duplice effetto, principi morali pratici, intenzione, casi paradigmatici, causa proporzionatamente grave.
Keywords: principle double effect, practical moral principles, intention, paradigmatic cases, proportionately serious reason.