Reasons, Reasoning and Rationality

Today at ANU concluded the conference on Reasons, Reasoning and Rationality, Themes From the Work of John Broome. Speakers: Jamie Dreier (Brown), Nic Southwood (RSSS), Andrew Reisner (McGill), Geoffrey Brennan (RSSS), Garrett Cullity (Adelaide), Daniel Star (CAPPE), Wlodek Rabinowicz (Lund), John Broome (Oxford). I won't try to do justice to all of the interesting papers, but instead will touch on a couple.

Jamie Dreier examined tensions between various formulations of two principles, which he aimed to reformulate and vindicate:

(Buck-Passing) For something to be good is for it to have properties that provide sufficient reason to choose, prefer, ... or admire it.

(Subjectivism) R is a reason for S to Phi iff R explains why Phi-ing promotes something S wants.

We had the most fun thinking about the Narcissus Bomb Example:

Philosopher chemists at Washington University have invented a Narcissus Bomb. Once triggered, this bomb will explode unless it is in the presence of someone who admires it enormously. You are now in the presence of a triggered Narcissus Bomb and nobody else is in the room.

This part of the talk was designed to show the limitation of Buck-passing. The explosive potential of the bomb is sufficient reason to admire it, but the bomb is evil. Jamie relied here on a fix by Nomy Arpaly, which hypothesizes that the bomb is sufficient reason to make it the case that you admire it but not reason to admire it.

I don't know yet how to think about reasons, but arguably a reason for Phi-ing is a reasoning Psi-ing when Phi-ing entails Psi-ing. But then since 'makes it the case' is factive, 'making it the case that you admire the bomb' entails 'you admire the bomb'. Hence, by the above closure principle, a reason for the former is a reason for the latter, and we're back to the original problem.

Another exciting paper was by Wlodek Rabinowicz, in which he argued Incommensurability is possible if there is vagueness. Incommensurability obtains when two thing x and y are such that neither is better than the other, yet they are not equally good. Wlodek was responding to an argument that Incommensurability is not possible. The argument depended on the following symmetry claim: if it is indeterminate that x is better than y then it's indeterminate that y is better than x.

Berit had a great counterexample to symmetry. Consider: x seems to have the temperature absolute 0. It's determinate that y doesn't seem colder than x, because on all sharpenings of the vague predicate 'seems absolutely cold' it is true that y doesn't seems colder than x. After all, y can't seem colder than absolute 0. But it's indeterminate that x seems colder than y, because on some sharpenings of the predicate 'seems absolutely cold' y doesn't seem absolutely cold. Hence, symmetry fails.