Tuesday, September 29, 2015

Against the "Sufficiency Principle" of Agential Promotion

Eden Lin recently got me thinking about (agential) promotion. By way of background: many views hold that we have reason to act a certain way iff so acting serves to promote a certain kind of outcome (e.g. valuable state of affairs, or the satisfaction of the agent's desires, or whatever).  Promotion of this kind might be thought to consist in probability-raising, for example, but there are disputes about the details, such as what the relevant "baseline" probability is for comparison purposes.  Eden's paper, 'Simple Probabilistic Promotion', (mentioned here with permission) identifies the following Sufficiency Principle as a commitment of many -- perhaps most -- of the philosophers in the literature:

Sufficiency Principle: S’s doing A promotes p if it causes p to obtain.

For example, Behrends & DiPaolo (p.4) offer the following case, where Julie supposedly "promotes" her desire by pressing the button, even though it's no more likely to be fulfilled than if she did nothing (it is guaranteed either way):
Buttons 2. Julie has some desire. There is one button in front of her. She knows that if she pushes the button, her desire is guaranteed to be fulfilled. However, unbeknownst to Julie, if she does not push the button, Black will ensure that her desire is fulfilled.

Eden convincingly argues that we needn't accept the sufficiency principle.  I'm inclined to think, stronger still, that we positively should not accept it.  Here's why.

We are interested in the notion of "promotion", I take it, just insofar as it is normatively significant -- related to what reasons we have.  But Julie has no (objective) reason to push the button in the above case.  To see this, note that any reason must have some positive weight, and thus be such that there could be some, weaker, countervailing reason that it could outweigh.  But Julie's putative reason to press the button in order to promote her desire could not outweigh any countervailing considerations whatsoever.  The very slightest cost would make it more worthwhile for her (objectively speaking -- she might not realize this, of course) to do nothing and let her desire instead be fulfilled by Black's backstage machinations.  So this putative reason, having zero normative weight, turns out not to be a normative reason at all.  So pressing the button does not "promote" Julie's desire, in any normatively significant sense.

(Or, I suppose, one could say that doing nothing promotes her desire equally well, and hence precisely counterbalances her instrumental reasons to press the button.  But this seems a merely verbal difference from saying that she has no reason to press the button at all, given that her desire will be fulfilled just as well either way.  And there seems no basis for insisting on the former way of talking -- or for rejecting views that involve the latter alternative -- as the Sufficiency Principle would require of us.)

[Update: Happy to see that Eden's final paper, now incorporating this argument, is forthcoming in PPR!]


  1. I'm not sure I quite see this. On one view about practical reason, we have reason to do the things that get us what we want -- even if there are other ways to get them. Imagine an agent faced with two buttons both of which would deliver the desired outcome. I'd think that she'd have a reason to press A and she'd have a reason to press B even though she could get what she wanted by not pressing A or get what she wanted by not pressing B. I think the reasoning you offer, though, would suggest that there's neither a reason to press A nor a reason to press B. The very slightest cost might deprive her of a reason to press A (or a reason to press B) but that doesn't seem like a good test of whether she has reasons in this case. If your case is different (and it might be), I suspect that the reason for the difference hasn't yet been articulated.

    1. Hmm, interesting. I think it's most natural to say the following: The agent does not have distinct reasons for pressing A than for pressing B. (They certainly don't have double reason to press both, for instance.) They simply have reason to do what will bring about the desired outcome, which is to say that they simply have reason to press either A or B. In other words, they have reason to ensure that they don't press neither.

      In cases like buttons 2, the analogous claim would be that Julie has reason to either press the button or not. But a reason to do (P or not-P) is irrelevant.

  2. Why do I feel we are skipping over evolution and survival and jumping completely into the current state. Had evolution not taken place and she was just provided for she would not be inclined to press either button. Looking upon the need and desire to perform may lie in the past of having to perform to be provided for.


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