The origin of behavior consistent with effective ("optimal") policies is an important topic in behavioral biology. In many cases, novel behavior patterns that emerge in unfamiliar situations are based on "trial and error" learning guided by rewards and punishments. The present work shows how an appropriate novel response canemerge full-blown in response to new contingencies if the situation has generic featuresthat can be recognized. This work is concerned with object retrieval, i.e., carriage of valued objects to a place of safety by Norway rats (Rattus norvegicus (Berkenhout); Rodentia: Muridae). Experiment 1 shows that selective retrieval of objects containing water over dry objects of the same material can occur immediately when rats are made thirsty; it is unlikely that this is a specific adaptation, since the opportunity to retrieve water in this way would rarely arise under natural conditions. Experiment 2 shows that without initial exposure to both objects under ad lib conditions (where the retrieval preference was for the dry objects), a process of trial and error is apparent as thirsty rats learn to select the appropriate object. It is argued that if object retrieval behavior is linked to a generic incentive feature and features such as wetness are receded into this general term, then appropriate object retrieval can be generated by a kind of deductive process. This type of generalist strategy would appear to be highly adaptive, in part because the usual tradeoffs between specialist and generalist strategies may not apply.

I defend the view that we act “under the guise of the good.” More specifically, I argue that an intention to do something is a belief that one ought to do it. I show how conflicts in intention and belief, as well as more complex impairments in these states, account for the central problem cases: akrasia in belief and intention, apparently unintelligible choices, and lack of motivation or accidie.

For most of your moral beliefs, there is at least someone out there who disagrees with you, but who is equally well informed and conscientious. How should you respond in situations of this kind? In my dissertation, I explain and defend a novel evaluative requirement for dealing with so-called peer moral disagreement. The evaluative requirement calls on us to assess our reasons for taking our interlocutor to be an epistemic peer. More specifically, it says that if these reasons are equally compelling to our reasons for accepting that our epistemic peer has made a mistake, then—and only then—are we warranted to substantially revise our belief or suspend judgment in our answer. This requirement has been ignored in the literature about peer disagreement. Without it, however, it is very difficult to make sense of our intuitive verdicts in cases of ordinary and extreme disagreement. According to the evaluative requirement, you are required to revise your belief in cases of ordinary disagreement but not in cases of extreme disagreement because in the former type of cases, but not the latter, our reasons for taking our interlocutor to be an epistemic peer are virtually equal to our reasons for accepting that our epistemic peer has made a mistake. The evaluative requirement is especially significant when we think about the problem of moral disagreement. There are two different forms that this problem can take. The first starts from the fact that there is no independent check that would confirm your moral beliefs over the beliefs of those who disagree with you, which allegedly undermines your moral knowledge. In response to this type of skeptical problem, I argue that it delivers the wrong verdict in cases involving cross-temporal disagreement. In the recent past, for example, there are many individuals who believed that slavery is morally permissible. This fact coupled with the independent check requirement implies that I do not know that slavery is morally wrong. Applying the evaluative requirement, I argue that our reasons for the claim that we know slavery to be morally wrong are much stronger than our reasons for the claim that we need an independent check to verify that our beliefs are true in a case of widespread moral disagreement. Thus, we should reject this independent check requirement. I then consider a second type of problem from moral disagreement. This problem starts not from the absence of an independent check in cases of disagreement, but from the fact of disagreement itself. A natural thought about such situations is that you are warranted to revise your moral beliefs in cases in which someone who is your cognitive and evidential equal disagrees with you. I argue that there is something else you can do in these situations besides revise your first-order beliefs, namely take steps to improve your epistemic position. Specifically, you can either improve your understanding of the reasons for thinking that your peer is mistaken (e.g. through additional research or reflection); or you can significantly improve your cognitive abilities in a way that's relevant to the disputed claim. It turns out that it is easier for the novice, as opposed to the expert, to escape this problem of moral disagreement because the novice has less epistemic work to do than the expert. The dissertation concludes by applying these lessons to the case of philosophical disagreement. Some philosophers have thought that any position like mine can be self-undermining. If, according to my position, we should substantially revise our beliefs in the face of peer disagreement, and if there are peer disagreements about views of disagreement, then we should substantially revise our belief in my position. Applying the evaluative requirement, I argue that in most cases of disagreements about views of disagreement, the individual who already accepts my position has compelling reasons for accepting it over accepting that so-and-so is her or his epistemic peer. This, of course, does not apply to everyone who accepts my position. Some might accept it for bad reasons, but this is not true of everyone who accepts it. Solving this self-undermining problem is another reason for accepting the peer evaluative requirement.

Extremism about Demands is the view that morality is significantly more demanding than prevailing common-sense morality acknowledges. This view is not widely held, despite the powerful advocacy on its behalf by philosophers such as Peter Singer, Shelly Kagan, Peter Unger, and G.A. Cohen. Most philosophers have remained attracted to some version of Moderation about Demands, which holds that the behavior of typical well-off people is permissible, including the ways that such people tend to employ their economic and other resources. It is difficult to resist the conclusion that proponents of Extremism have not taken sufficiently seriously the central convictions that motivate the Moderate view.

This dissertation offers an improved defense of Extremism about Demands. At its center is an argument that appeals dialectically to requirements of justice that Moderates themselves already implicitly accept. Specifically, I claim that any plausible set of Moderate moral principles will, when applied to a world like ours, yield demands on typical well-off people that far exceed the demands of common-sense morality.

My argument has two cruxes. The first is the idea that our concern for justice is at least partially grounded in a concern for individuals’ interests, broadly construed. The other is a principle that I call Injustice entails Obligations, which says that we are collectively subject to requirements of justice that, if fully complied with, would ensure the transition from current injustice to a just state of affairs. Any view that is compatible with both the interest-based view of (part of) our concern for justice and Injustice entails Obligations will, I argue, require sacrifices from typical well-off people that substantially exceed what prevailing common-sense morality requires of them.

Moderates typically emphasize the idea that each person has an important interest in pursuing the projects, plans, relationships, and commitments that are most important to her. But they also believe that acceptable Moderate principles will properly balance this idea with the idea that from a properly impartial perspective everyone, and everyone's interests, are equally morally important. Because Moderates accept the latter idea, they are already committed to thinking that in a just world, everyone would have a sufficient minimum share of society’s resources. I argue that even if we limit our focus to distributive justice in a single society such as the United States, and even if we assume that distributive justice requires only a sufficient minimum, the extent to which the status quo must be transformed in order for justice to be achieved is still too great to be compatible with Moderate demands on typical well-off people.

There are a number of ways to try to argue that Moderate principles and Injustice entails Obligations are compatible with Moderation about Demands. For instance, it might be argued that all or nearly all of the demands to sacrifice in order to promote justice can be assigned to the super-rich, rather than to typical well-off people. Or it might be argued that the sacrifices of a single well-off person cannot be required because they amount to a mere “drop in the bucket” relative to what needs to be done in order to fully achieve justice. I show that such arguments fail.

The argument that I consider in greatest detail derives from John Rawls’s view that the principles of justice apply to the institutions of the “basic structure of society,” and do not apply directly to the conduct of individuals. If this “Institutionalism” is right, then it cannot be the case that individuals are obligated to promote justice directly in the way that I suggest they are. Furthermore, it might seem that a view that assigns all of the burdens of promoting justice to the basic structure satisfies the imperative to transition from injustice to justice, since if the relevant institutions were to begin doing everything that the Rawlsian view says they ought to be doing, the requirements of justice would be met. I argue, however, that there is no understanding of Institutionalism on which it is itself consistent with the following desiderata: Moderate principles, and the associated interest-based view of (part of) the ground of our concern for justice; Injustice entails Obligations; and Moderate demands. So, Institutionalism cannot make Moderate principles and Injustice entails Obligations compatible with Moderate demands.

Moderate principles and Injustice entails Obligations, then, remain incompatible with Moderation about Demands. Since there are compelling reasons to accept both Moderate principles and In justice entails Obligations, I conclude that we must reject Moderation about Demands. The obligations that justice places on typical well-off people are substantially more extensive than is acknowledged by prevailing common-sense morality.

We value many things for their historical significance--for instance, the Parthenon, Gettysburg, the redwood forests, and the tea ceremony. While they may also be beautiful, educational, or useful, we often value them simply in virtue of their historical properties. This mode of valuation carries with it a suite of common assumptions: what we value for its history is irreplaceable, it demands preservation, and we should value it only if we have a personal stake in its history. My dissertation interrogates these seemingly intuitive commitments, and explores the moral, evaluative, and political consequences of rethinking them. I develop an account of the norms governing our interactions with historically valuable objects and places, yielding an improved understanding of the values latent in such diverse examples as heirlooms, relationships, artworks, artifacts, and historic sites. It also, I argue, sheds light on other important sources of value, including persons and the natural environment.

It is often thought that things worth valuing for their historical properties are necessarily irreplaceable, and that this fact makes a defining contribution to their distinctive value. For example, no candidate substitute can be valuable in the same way as my father's ring. Against this widespread view, I argue that a plausible understanding of historical significance entails that many things we value for their histories are not irreplaceable after all. What makes historically significant things worth valuing is not their irreplaceability, but rather the connection with the past that they afford.

This raises the difficult question of how we can best realize a connection with the past. I argue that historical value, like value in general, fundamentally involves reasons to engage appropriately with valuable things: that is, to respond to them in a manner sensitive to the specific ways in which they are valuable, for instance, by viewing a painting, playing a sport, or savoring a fine meal. This contrasts with the views of many philosophers, who believe that the value of objects fundamentally involves reasons to preserve them. As I argue, reasons for preservation are subordinate to and explained by reasons for engagement--there is no reason to preserve even the Mona Lisa if no one can have the opportunity to engage with it. Recognizing the centrality of engagement in evaluative theory and practice has extensive implications, both in historical cases and beyond.

Consider the distinction between personal and impersonal value. It is natural to think that some objects (such as family heirlooms) have merely personal value, whereas others (such as the pyramids or the Grand Canyon) have value for anyone. But how exactly are we to understand this distinction? Traditional accounts suggest that things are impersonally valuable if they would be valued from a suitably "detached" perspective. But I show that this criterion does not reliably identify things of impersonal value. On the alternative framework I propose, an object's value is impersonal if and only if it is appropriate (and therefore evaluatively permissible) for anyone to engage with it. Only a few people have reason to engage with a family heirloom, whereas the pyramids are candidates for universal engagement. Moreover, this account leaves open the possibility that the reasons that each individual has to value the pyramids can vary with that individual's particular history, interests, and capacities, unlike the shapeless "agent-neutral" reasons of the traditional view.

Finally, I argue that the historical mode of valuation is often properly understood as a kind of aesthetic valuing. While many twentieth century philosophers have acknowledged the importance of art historical properties to aesthetic evaluation, I distinguish between art historical properties and the more general historically significant properties that are found both within and beyond the artworld. I then argue that these historical properties can be accommodated on a number of influential accounts of aesthetic value, and indeed, that they comprise an important dimension in aesthetic experience. This helps cement the extension of aesthetic inquiry beyond the artworld, and articulates a familiar yet surprising way in which we engage with the past.

Collective Harm Cases pervade the modern world. In these cases, people collectively cause harm, or fail to prevent it, but no individual seems to make a difference. For example, while climate change is caused by millions of people acting in certain ways (driving in cars, flying in planes, using coal-generated electricity, etc.), it seems that no individual such act will make a difference. Similarly, while the large-scale consumer patterns of wealthy nations can affect the lives of people in poorer nations, it is hard to believe that any individual purchase will make a difference for the worse. In cases of this sort, if it is true that no individual act will make a difference, it is unclear how we can say that anyone ought, or even has reason, to act otherwise. But if we cannot, this would be very troubling. Morality would be powerless in a wide array of cases in which it should have force. This is the Problem of Collective Harm.

I argue that the key to solving the Problem of Collective Harm is to reject a standard, intuitive assumption that underlies it. The assumption is that if an act cannot make a difference with respect to an outcome, then it cannot play a morally significant, non-superfluous causal role in bringing that outcome about. Or, to put it another way, we must reject the assumption that helping to bring about an outcome requires making a difference to it. This assumption is highly natural, but I argue that it is mistaken and that once we see that it is mistaken, the central puzzle of the Problem of Collective Harm is resolved.

Chapter 1 is devoted to setting out the problem and how I will approach it. Chapters 2 and 3 discuss a range of proposed solutions that have been put forth by others. The upshot of the critique of these views will be that we cannot solve the Problem of Collective Harm unless we can reject the assumption that helping requires making a difference. In Chapter 4, I turn to my positive proposal. There I give an account of what is required for an act to help to bring about an outcome, where this does not require being able to make a difference. I use this account to explain our reasons for action in Collective Harm Cases, and I give an error theory that explains why the standard assumption seems right, even though it is not. In Chapter 5, I highlight some noteworthy features of my proposal and some important questions about it that still need to be addressed.