Im Sinne des nun erweiterten Einsatzbereichs dieses Blogs hier nun also die Präsentation zu dem Vortrag, den Sabine und ich am Montag auf der Konferenz Rational Agency gehalten haben. Unter der Präsentation (auf den Pfeil klicken) findet sich eine Kurzzusammenfassung.
In the following, we shall present a critique of decision theory as a normative account of decision making under risk. We claim that decision theory has to be supplemented by virtue. To some of you (especially to non-philosophers), speaking of “virtue” might sound old-fashioned or even humorous. But we use it as a technical term that refers to a person’s capability to assess risk appropriately in an immediate, specific kind of perceptual way, rather then in an intellectually calculating way. Virtuous risk assessment manifests itself both in its possessor’s sensibility towards risk and in his being motivated to act accordingly. To establish that decision making under risk requires virtue, we will, first of all, show that decision theory is unable to resolve the well-known St. Petersburg paradox. The St. Petersburg game poses a long standing problem to decision theory because it has infinite expected value and yet seems to be worth much less. As we shall argue, the systematic deviation from putatively rational choice can be justified as an instance of virtue. In support of this argument, we will establish that, contrary to common belief, decision situations can be found in real life which entertain the structure of the St. Petersburg game, or rather of the inverted St. Petersburg game which we shall introduce. We maintain that in many cases the assessment of risky technologies is such that a decision has to be made about possible but extremely unlikely outcomes with an “infinite” negative value (so to speak). In these cases, virtue is needed to avoid an inappropriate assessment of these options by a decision theory that is expected to do too much – or so we shall argue.