I MAGINE A DOCTOR WHO IS FACED with a patient's disease that she knows will lead to death unless treated shortly. (1) Two possible treatments are available: A and B. After careful consideration of the available evidence, the doctor concludes that treatment A will cure the patient, and B will kill him. Unbeknownst to her, however, in fact treatment B is the cure, while A will lead to the patient's death. What ought the doctor to do: give A or give B?
Let us call facts about a person's beliefs, knowledge or evidence facts about that person's perspective. We may then ask more generally: Does what an agent ought to do depend on the agent's perspective, or is it perspective independent? Objectivists about "ought," such as G. E. Moore and J. J. Thomson, claim that "ought" is independent of the agent's perspective. (2) Hence, they would hold that the doctor ought to give treatment B--the one that in fact cures the patient. Perspectivists like H. A. Prichard and W. D. Ross, on the other hand, believe that "ought" depends on the perspective of the agent--a view that is sometimes spelled out in terms of the agent's actual beliefs, and sometimes in terms of the evidence available to the agent. (3) Both of these versions of perspectivism hold that the doctor ought to give A, not B.
Others again try to solve the puzzle by distinguishing different senses of "ought." (4) According to them, all that we can say is that the doctor ought to give A, relative to her perspective, and that she ought to give B, relative to all the facts. I am willing to concede that it might be useful to speak of what an agent ought to do relative to certain considerations, and that different qualified notions of "ought" might be important in their own right. Nevertheless, I believe that there is a substantial question at issue between objectivists and perspectivists when it comes to what might be called the "overall ought" of practical deliberation. This is the concept involved in the deliberative question, "What ought I to do?" (or "What should I do?") and deliberative conclusions of the form, "I ought to [phi])" (or "I should [phi]"). (I take "ought" and "should" to be equivalent, but for simplicity's sake, I will mostly use "ought" in what follows.) Practical conclusions of this sort are supposed to guide rational decision-making and action directly. In other words, the "ought" at issue is the one that is appealed to in the common idea that it is irrational, or akratic, not to intend what one believes one ought to do. (5) Now, in order to make a rational decision guided by a belief that one ought to do something, one needs a univocal concept of "ought" that figures in such beliefs. It is perfectly consistent to believe, "I ought to [phi]), relative to X," and, "I ought not to [phi]), relative to Y," but one cannot rationally intend both to [phi] and not to [phi]). There must be one sense of "ought," the belief in which is the relevant one for decision-making. We need to be able to judge, "I ought to [phi], full stop." At any rate, this is what I shall assume in the following discussion.
The concept that is (inter alia) used in such deliberative conclusions is sometimes called the "practical ought." (6) I think it is natural to consider the practical "ought" as the central, unqualified sense of "ought" and regard all other "oughts" as qualified senses. (7) This claim, however, will not function as a substantial assumption of the argument. This paper is about the question of whether the practical "ought" depends on perspective, and I will refer to this concept by using the word "ought" without qualification only for the sake of convenience. Against this background, we can understand objectivists and perspectivists as disagreeing about the question as to which of the qualified senses of "ought" that are relativized to a certain body of propositions (such as the body of all true propositions, all believed propositions or the propositions that constitute the agent's evidence) provides the correct truth conditions for the practical "ought":
Objectivism: A ought to [phi] if, and only if, A ought to [phi] relative to all facts. (8) Belief-relative perspectivism: A ought to [phi] if, and only if, A ought to [phi] relative to A's beliefs. Evidence-relative perspectivism: A ought to [phi] if, and only if, A ought to [phi] relative to the evidence available to A. (9) The aim of this paper is to defend a version of perspectivism, but I will be concerned with the evidence-relative view only. The belief-relative (or "subjective") view is problematic for several reasons; for example, it seems to entail that one can escape an ought-claim if one does not believe an inconvenient truth one has overwhelming evidence for. A detailed discussion of this view, however, is beyond the scope of this paper. Here I will simply assume that a plausible perspectivist position will be spelled out in terms of evidence, i.e., in terms of whatever it is that justifies or warrants belief (and disbelief), rather than what is actually believed. (10)
I shall begin, in section I, by setting out the debate between objectivists and perspectivists. Drawing on an example by Frank Jackson and the literature that has arisen from the discussion of this and structurally similar examples, I motivate perspectivism by showing that, unlike objectivism, it provides us with a plausible account of normative guidance. In the main part of the paper (sections II--VI), I discuss a set of problems which many, including myself, take to be the most serious challenge to perspectivism: First, if what an agent ought to do depends on her limited information, how can a better-informed adviser give good advice to this agent in terms of what the agent ought to do? Second, how can we understand an agent's seeking new evidence, or an adviser's sharing evidence not yet available to the agent, as ways of finding (or helping to find) an answer to the agent's deliberative question, "What should I do?" if the correct answer to that question depends on the agent's perspective? My aim is to develop a perspectivist account that answers these questions by paying close attention to the role of time in the truth conditions of ought-judgments. In section VII, I conclude with a summary of the results achieved.
In response to the above-mentioned problems for perspectivism, some philosophers have recently argued for relativist theories of "ought," according to which what an agent ought to do does not depend on the perspective of the agent herself, but on the perspective of the speaker, or even the assessor, of the ought-statement. (11) Such accounts raise their own problems, for example by allowing for a multitude of practically incompatible truths about what an agent ought to do at a given time, but a discussion of these views lies beyond the scope of this paper. However, a defense of perspectivism--the view that the practical "ought" invariantly relates to the perspective of the agent--will help to undermine the need for such relativist accounts, which are generally motivated by the supposed failure of non-relativist accounts to resolve the problems in question.
Objectivism vs. Perspectivism
When we make up our mind about something, we normally take the object of our thinking to be independent of our perspective on it. objectivists hold that things are not any different when it comes to thinking about what we ought to do. As a consequence, an agent's belief that she ought to do something could be perfectly justified by her evidence--and yet false. Perspectivists, on the other hand, claim that the truth we seek in practical deliberation does itself depend on our evidence. Some motivate this view by drawing attention to the normative relevance of epistemic risk; others by pointing to the plausible connection between what we ought to do and what we are responsible for doing. The most pressing problem for objectivism, however, is that it cannot account for guidance under conditions of uncertainty. It is here that perspectivism seems overwhelmingly more attractive than objectivism. Consider the following example by Frank Jackson:
Jill is a physician who has to decide on the correct treatment for her patient, John, who has a minor but not trivial skin complaint. She has three drugs to choose from: drug A, drug B, and drug C. Careful consideration of the literature has led her to the following opinions. Drug A is very likely to relieve the condition but will not completely cure it. One of drugs B and C will completely cure the skin condition; the other though will kill the patient, and there is no way that she can tell which of the two is the perfect cure and which is the killer drug. What should Jill do? (12) As Jackson points out, objectivists give the intuitively false answer to that question. Since it is a matter of fact that one drug (either B or C) completely cures the patient, objectivism entails that Jill ought to give that drug. objectivists therefore have to say that Jill either ought to give drug B or ought to give drug C. But giving B and giving C both involve a 50 percent epistemic risk of killing Jill's patient, John, a risk that is clearly not outweighed by the 50 percent chance of curing John's minor skin complaint. No doubt, the only responsible thing for Jill to do is to give drug A, but unless we take into account her perspective, we cannot say that she ought to give A. Hence, perspectivism is much better equipped to deal with the example than objectivism. (13)
A common reply on behalf of objectivism is to introduce a distinction between what agents ought or ought not to do, on the one hand, and what they are to be praised or blamed for, on the other. (14) objectivists agree that it would be unreasonable or blameworthy for Jill not to give drug A, but maintain that it simply does not follow that she ought to give that drug.
The problem with this reply is that it leaves entirely open how Jill could be...