Friday, 13 June 2008

Davidson on Weakness of Will (Part 2)

In my previous post, I suggested that Davidson's bipartite account of practical reasoning is able to preserve the consistency of (P1)-(P3). However, there is a worry that Davidson’s solution leaves it unclear how the weak-willed agent can be said to be motivated by her reasons. This is the objection I wish to consider in the present post.

According to Davidson, the akrates acts for a reason, but not from her all-thing-considered judgement. Recall that in our example, Mr. Smith has three prima facie judgements—(c), (d) and (e)—each of which is relative to some set of reasons:
(c) Prima facie, having a third glass of wine is better than not having a third glass of wine, given r1.

(d) Prima facie, not having a third glass of wine is better than having a third glass of wine, given r2.

(e) Prima facie, not having a third glass of wine is better than having a third glass of wine, given R.
However, Mr. Smith (being weak-willed) ultimately decides to have a third glass of wine, against his all-things-considered judgement.

In the case of the continent agent, the action generating sans phrase judgement corresponds with the agent’s all-things-considered prima facie judgement. That is, the continent agent acts from her total set of reasons. However, in the case of Mr. Smith, his sans phrase judgement corresponds with (c) rather than (e). Hence, Mr. Smith (i.e., the incontinent agent) acts from a subset of his reasons, r1, instead of his total set of reasons, R. Herein, according to Davidson, lies the irrationality of the incontinent agent; she fails to perform the action judged best on the basis of all her reasons.

However, as limned above, there seems to remain a gap in Davidson’s account. On his picture, an agent’s prima facie judgement is always relative to some reason. However, an agent’s sans phrase judgement is not. This opens up a lacuna between one’s reasoned-based evaluations and one’s action generating judgements. Davidson attempts to fill this gap via what he refers to as the “principle of continence”:
(POC) Perform the action judged best on the basis of all available relevant reasons.
Davidson insists that (POC) is a principle that is binding on every rational agent, the violation of which constitutes the fundamental shortcoming of the akrates. Hence, Davidson believes that there is a normative imperative to always act from one’s total reasons. Strictly speaking, as worded by Davidson, (POC) is unable to bridge the logical gap between an agent’s prima facie judgements and her sans phrase judgements. However, we can equip it for this purpose by rephrasing it as follows:
(POC*) Do what is prima facie better, given R.
With the revised version of the principle of continence in place, the logical gap between an agent’s prima facie and sans phrase judgments has been bridged.

However, there still remains a motivational gap; a fact which the possibility of incontinence illustrates. If the principle of continence were sufficient to bridge the motivational gap between an agent’s prima facie and sans phrase judgements then any agent who was rationally committed to the principle of continence would be immune to weakness of will. However, such a conclusion seems implausible since it would imply that the akrates suffered from an extreme intellectual defect. Recall, Davidson invokes the principle of continence as a rule that every rational agent should accept as such. Consequently, to suggest that the akrates believes that she is not rationally obliged to act in accordance with the principle of continence is, by Davidson’s lights, to drum her out of the ranks of rational agents altogether

Davidson’s distinction between prima facie and sans phrase judgements drives a wedge between an agent’s reason-based practical assessments and desire-based motivations. On the one hand, one’s prima facie judgements are always relative to a set of reasons while one’s sans phrase judgements are not. On the other hand, only sans phrase judgements, according to Davidson, are expressive of one’s wants and therefore only sans phrase judgements can be said to motivate. The upshot seems to be that, on Davidson’s account of practical reasoning, one cannot be directly motivated by one’s reasons.

Another way to make this problem vivid is by posing the question: is (POC*) a prima facie or sans phrase judgement? There two considerations that tell against it being the former. First, it is not of the right logical form. (Although (POC*) represents a judgement about an agent’s prima facie judgements, it is not itself a prima facie judgement.) Second, if it were a prima facie judgement (assuming we were able to reformulate it somehow), it would be unable to bridge the motivational gap between Davidson's two stages of practical reasoning. (POC*) must implicate the desires of the agent if it is to serve the motivational role necessary. However, as we noted above, prima facie judgements fail to implicate the desires of an agent. On the other hand, (POC*) cannot be a sans phrase judgement since it does not consistently generate action (as the possibility of incontinence illustrates).

The suggestion that there is a motivational gap between an agent's prima facie and sans phrase judgements seems problematic since it seems to fly in the face of Davidson’s foursquare insistence that one is caused to act by one’s reasons.

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