Some people say that it is inappropriate to hold moral principles in a way that is immune to empirical falsification. G.A. Cohen and T.M. Scanlon disagree. I have not thought about these issues but I don’t get the alternative to the picture Cohen and Scanlon argue for. A first stab might be that what would count as an empirical falsification would be that results the theory predicts don’t materialize. For example, perhaps some will claim that lowering the minimum wage is good because it benefits the worst off. This is surely an empirical claim and surely empirical evidence could possibly show it to be false. And if there are people who refuse to accept that then they are silly. But what this seems to me to show is that we need to distinguish between the intrinsically morally recommended goal and the means that are thought to be useful for bringing about that goal. Of course empirical findings are relevant to understanding what causes what. No pressure is placed upon the moral view that we should especially worry about the worst off by showing such empirical findings.

But pressure from thought experiments can also surely get us to change our minds about what the intrinsic goal of morality is. We might think that maximizing welfare is the intrinsic goal of morality but considering possibilities might get us to realize that this goal can be satisfied in ways that are not morally ideal if, for example, the way to maximize the sum total of welfare would involve vast resources going to a utility monster. This just involves ordinary non-empirical considerations in favor or against this or that as being the intrinsic moral goal. What I do not yet see is how, after we have done all the non-empirical work of settling for ourselves what the intrinsic goal of morality is, how empirical considerations provide evidence for or against such an understanding. Essentially, it seems to me that the relevance of empirical claims to determining the intrinsic moral goal is best understood to be subsumed by non-empirical moral conditionals. I think Scanlon says something very much like this.

Take a person who has a fully worked out view for every possibility of the form "if the empirical world works this way, then that is the morally correct action." That so far seems to me a completely non-empirical theory as it does not at all have to peek at which possible world is actual. I take some people out there to be saying that which possible world is actual, that is, genuinely empirical matters, are directly relevant to assessing the intrinsic moral goal. I don't understand how that picture is supposed to go.