Here’s an argument against subjectivism about moral wrongness I’ve been kicking around. (By ‘subjectivism’ here I just mean any theory which is not “objective”—that is, a subjective theory is one that has it that that in virtue of which one’s behavior is wrong (when it is wrong) is either one’s beliefs about, or one’s evidence concerning, one’s situation.) I thought I’d post it and see if it has any legs.
Here goes. The argument starts, as do many, with a case. (I apologize in advance for the length and complexity of the case—as with all complex cases, the bells and whistles are meant to forestall a number of possible replies and objections; despite the case’s complexity, the intuition I have about it to which I appeal in my argument seems fairly robust to me.) Here’s the case:
APPLE: On Monday evening I villainously programmed a robot to kill Bloggs on Wednesday morning (Bloggs beat me out of first place in the local chess championship and I was, shall we say, quite a bad loser.) It’s now Tuesday morning and I’ve come to repent my horrendous behavior the previous evening. I now desperately want to stop the robot from killing Bloggs tomorrow morning. Unfortunately I can’t now do anything to stop the robot. I do know, however, that one way of preventing the robot from killing Bloggs on Wednesday morning is to press a certain button—button B—later this evening (i.e., Tuesday evening) which will deactivate the robot (the button is, unfortunately inactive right now (i.e., Tuesday morning)). There are only two things that I can do now on Tuesday morning: (a) eat the apple I have in my hand or (b) not eat the apple I have in my hand. My nemesis, the nefarious Jones, is present and tells me what he will do if I do either of my options. (Jones is a weird dude, but he always can do and does what he says he’ll do.) So, of each of my options I know now, on Tuesday morning, what will indeed happen between now and Wednesday morning if I choose it. Here is what I know:
(a) I know that if I now eat the apple, between now (Tuesday morning) and later this evening (Tuesday evening) I am going to forget entirely about Bloggs and the fact that I set a robot in motion to kill him. (I know this because Jones has told me he’ll make me forget between now and then if I eat the apple.) I also know that if I eat the apple, later this evening (Tuesday evening) I will believe falsely, though justifiedly and in accord with all my evidence then (on Tuesday evening), that pressing B will have one and only one effect: causing Smith to be electrocuted to death. (I know this because Jones has told me that if I eat the apple he’ll rig things up so that all of my evidence this evening will indicate that pressing the button will electrocute Smith to death.) I hate Smith—my spouse, over the past two years, has engaged in an affair behind my back with him, an affair Smith had no idea he was engaging in (my spouse never told Smith about me) and about which I have only recently found out. I know it would be wrong to kill Smith (he’s entirely innocent) and am now (on Tuesday morning) not at all inclined to kill him. But I also know that if given the opportunity to kill him later this evening I will nonetheless then do so. Because of all of this, I know that if I now eat the apple I have in my hand I will later this evening press button B, justifiedly believing at that time that I am killing Smith by doing so. (I also know I’d be able then to refrain from pressing the button then; but even so, I know I’d press it nonetheless.) Finally I also know that if I do eat the apple and then go on to press button B this evening thinking I am killing Smith by doing so (but, in fact, unbeknownst to me then, saving Bloggs from being killed by the robot Wednesday morning), no one will know I did so and I’ll forget having done so one minute after doing it. (Let’s say Jones has told me he’ll ensure this as well (remember, he’s a weird dude)).
(b) I know that if I do not now eat the apple both (i) I won’t have the option of pressing button B later this evening (Tuesday evening) because Jones will destroy button B between now and then and also (ii) later this evening Jones will give me the opportunity to save Bloggs from the robot I’ve set in motion to kill him Wednesday morning, but at the cost of my leg. (Nefarious Jones will deactivate the robot himself if I chop off my own leg, but not otherwise.) I also know that if I don’t eat the apple now and Jones does make me that offer later this evening, I will chop off my own leg and thereby save Bloggs from being killed by the robot Wednesday morning. (I also know now (Tuesday morning) that were I to chop off my leg to save Bloggs later this evening (Tuesday evening) I’d be able to refrain from doing so then; but even so, I know I’d chop it off to save Bloggs nonetheless.)
Now here’s the argument: If I am a morally conscientious person on Tuesday morning, it seems to me, it need not be the case that I’m strongly motivated not to eat the apple. (Of course I wasn’t morally conscientious the night before, when I activated the robot, and I won’t be morally conscientious later this evening if I do eat the apple now, for I’ll attempt to kill Smith then if I eat the apple now. But despite all of that, surely it could be the case that on Tuesday morning I’m being morally conscientious.) But if any plausible subjectivism were true and I knew the true moral theory, then I’d know that I’m facing a choice on Tuesday morning between doing something (viz., not eating the apple) that will neither be wrong nor lead to my doing anything wrong at any time—not eating the apple surely isn’t wrong and later chopping off my own leg to save Bloggs’s life certainly wouldn’t be wrong then—and doing something (viz., eating the apple) that will lead to my doing something horribly morally wrong—eating the apple will lead to my later doing something horribly morally wrong by the lights of any plausible subjectivism (viz., doing something I believe, and all my evidence indicates, will kill an innocent person (and gruesomely to boot!)). But here, it seems to me, is a conceptual truth about moral conscientiousness:
(*) Necessarily, a morally conscientious person, if faced with a choice between doing something that will result in her not doing anything wrong then or ever after and her doing something that will result at some point in her acting horribly morally wrongly, she will be strongly motivated not to do the thing that will result in her acting horribly morally wrongly.
It follows, then, however, that if (i) I am morally conscientious on Tuesday morning in APPLE, (ii) any plausible subjectivism is true, and (iii) I know the true moral theory on Tuesday morning in APPLE, then I am strongly motivated not to eat the apple. But since it has to be possible that I both be morally conscientious and know the true moral theory on Tuesday morning in APPLE, it must not be the case that any plausible subjectivism is true.
Here’s the argument, I believe, a bit more rigorously (and pedantically) formulated:
1. Necessarily [a morally conscientious person, if she knows she is faced with a choice between doing something that will result in her doing nothing wrong ever and her doing something that will result in her acting horribly morally wrongly, she will be strongly motivated not to do the thing that will result in her acting horribly morally wrongly]. (Premise—Purported conceptual truth (*))
2. Necessarily, [if [subjectivism is true & I believe the true moral theory on Tuesday morning in APPLE], then in APPLE, I know on Tuesday morning that I face a choice between doing something that will result in my doing nothing wrong then or ever after (not eating the apple) and doing something that will result in my at some point acting horribly morally wrongly (eating the apple)]. (Premise)
3. Therefore, necessarily [if [subjectivism is true & I believe the true moral theory on Tuesday morning in APPLE], then [if I am morally conscientious on Tuesday morning in APPLE, then I am strongly motivated not to eat the apple on Tuesday morning in APPLE]]. (from 1 & 2)
4. It is possible that [(i) I believe the true moral theory on Tuesday morning in APPLE & (ii) I am morally conscientious on Tuesday morning in APPLE & (iii) it is not the case that [I am strongly motivated not to eat the apple on Tuesday morning in APPLE]]. (Premise)
5. Therefore, it is possible that [it is not the case that [subjectivism is true]]. (from 3 & 4)
6. Necessarily, [if [it is possible that [it is not the case that [subjectivism is true]]], then [necessarily [it is not the case that [subjectivism is true]]]. (From the necessary truth of whatever moral theory happens to be the true one)
7. Therefore, necessarily [it is not the case that [subjectivism is true]]. (from 5 & 6)
*(This argument depends for its cogency on my having knowledge at one time about how I will voluntarily act (i.e., act in such a way that at the time of my so acting I could have acted otherwise) in the future were I to choose a particular option now that I don’t in fact choose. This is middle knowledge, and some think it is contentious that I could have it. (Some deny that God has middle knowledge!) I don’t think it’s implausible at all that I have this kind of knowledge—for instance, on election day 2008 I walked into booth #1 and pressed the booth #1 lever for Obama; however, before entering booth #1, I then knew both that I could instead have walked into booth #2, and also that were I to do so I would voluntarily press the booth #2 lever for Obama. That said, some might still balk at anyone’s having this kind of knowledge of counterfactuals of freedom. (I should also note, in passing, that the possibility of this kind of knowledge is presupposed by the actualism and possibilism debate in ethics. If appealing to it there is fair game, so too should it be here.) All of this notwithstanding, I believe an argument for the same conclusion, one without any loss of force, could be given that only made appeal to the probabilistic counterfactual knowledge I have about my own future actions. Surely I know myself well enough to have some such knowledge about my future actual and counterfactual behavior!)
**(For those who are inclined to split senses—those who think that there is an objective ‘morally wrong’ and also a subjective ‘morally wrong’—construe this argument as an argument for the claim that the ‘morally wrong’ that is of interest to the morally conscientious person in her deliberations about what to do is not the subjective ‘morally wrong’.)
***(The cogency of this argument may well depend on the falsity of consequentialism. I assume for the purposes of this argument that consequentialism is false. (I also believe that consequentialism is false.))