Foltern um zu retten? Der argumentative Gebrauch von Gedankenexperimenten

Wie überzeugend sind Gedankenexperimente in der Ethik? Aus mehr oder weniger aktuellem Anlass schrieb Michael Kinsley in Slate Mitte Dezember eine durchdachte Auseinandersetzung mit Charles Krauthammers Wiederbelebung des "Folter einen, rette viele"-Gedankenexperiments (gefunden via Patrick Baums Weblog Philosophus). Die moralische Frage ist hier im Zusammenhang eines möglichen US-Gesetzes zu sehen, es geht also eigentlich darum, ob ein Gesetz Folter verbieten oder erlauben oder mit welchen Restriktionen erlauben sollte. Kinsleys Schlussgedanke begegnet auch in der Auseinandersetzung mit ethischen Gedankenexperimenten, nämlich: Spezielle Fälle sind kein guter Ratgeber beim Test unser moralischen Intuitionen, und sie zeigen nicht, dass das jeweilge moralische System fehlerhaft ist, wenn es damit nicht klarkommt. Kinsley im O-Ton:

There is yet another law-school bromide: "Hard cases make bad law." It means that divining a general policy from statistical oddballs is a mistake. Better to have a policy that works generally and just live with a troublesome result in the oddball case. And we do this in many situations. For example, criminals go free every day because of trial rules and civil liberties designed to protect the innocent. We live with it.

Of course a million deaths is hard to shrug off as a price worth paying for the principle that we don't torture people. But college dorm what-ifs like this one share a flaw: They posit certainty (about what you know and what will happen if you do this or that). And uncertainty is not only much more common in real life: It is the generally unspoken assumption behind civil liberties, rules of criminal procedure, and much else that conservatives find sentimental and irritating.

Sure, if we could know the present and predict the future with certainty, we could torture only people who deserve it. Not just that: We could go door-to-door killing people before they kill others. We could lock up innocent people who would otherwise be involved in fatal traffic accidents. Civil libertarians like to believe that criminals get their Miranda warnings and dissidents enjoy freedom of speech because human rights are universal. But if we knew for sure that a newspaper column by Charles Krauthammer would lead—even by a chain of events he never intended and bore no responsibility for—to World War II, wouldn't we be nuts not to censor it? Universal human rights would make no sense in a world where everything was known and certain.

This is not to say that Krauthammer's killer hypothetical could never happen. It is to say that morality does not require us to build a general policy on torture around a situation that is not merely unlikely in real life, but different in kind from the situations we are likely to face in real life. What we would do or should do if this situation actually arose is an interesting question for bull sessions in the dorm, but not a pressing issue for the nation.