Why should anybody care about theoretical simplicity? It is pretty clear that simpler theories don't stand a better chance of being true, just because they are simpler than their competitors. Of course, simpler theories are easier to use in technological applications, and they are more tractable. But that is something engineers should be concerned about. Why should the theoretical scientist be interested in simple theories? The principal virtue of simple theories is their facilitation of scientific understanding in virtue of their greater explanatory power. Simple theories are more unified, and they allow important kinds of reasoning about the world. If a theory yields a unified but structure-rich picture of the world, and thereby a high degree of understanding, we can design relevant experiments, form rational expectations, and in general are in a better position to gather relevant data than when we confront the world without any understanding whatsoever. Simple theories are therefore, in virtue of increasing our understanding, epistemically advantageous. That's why the theoretical scientist should be interested in simple theories. Of course, since the choice of simple theories does not guarantee getting closer to the truth, the claim that such a choice is epistemically advantageous presupposes that we draw a distinction between the explanatory power of theories and their accuracy. This distinction has not received sufficient attention in the existing literature, and that's why it was so difficult to say exactly what the virtue of simple theories is. Recognizing that explanatory power and accuracy are orthogonal aspects of scientific theories allows us to assign simplicity the role of facilitating understanding and thereby guiding controlled experimentation.

It is a commonplace to hold that faultless mistakes of fact justify--or, at least, excuse--an agent's actions. Less prominent, however, is the view that faultless mistakes about morality similarly come to bear on our attributions of moral blameworthiness. My aim in this dissertation is to defend what I call the symmetry thesis: faultless mistakes of morality excuse just as do faultless mistakes of fact. Opposition to this thesis, I think, falls out of an incorrect understanding of the way in which faultless mistakes of fact come to bear on our attributions of moral responsibility. Accordingly, much of the dissertation is composed of an analysis of the excusing force of faultless mistakes of fact. Chapter 1 argues that faultless mistakes of fact are appropriately deemed excused, not justified, by morality and the law. Chapter 2 develops a challenge to what I call the traditional analysis of the excusing force of mistakes. This view holds that an agent's faultless mistake is excusing if, and only if, the mistake undermines, displaces, or, as they say in the criminal law, "negatives" the agent's subjective culpability. I suggest that concerns about voluntariness, not subjective culpability, are in order. Chapter 3 develops an account of voluntariness. I argue that an agent's actions are voluntary enough for an attribution of responsibility only if he did what he is accused of doing because this is something he was willing to do (in the fashion in which it was done)--only if, that is, what he did conforms to his will. Chapter 4 then applies this account of the excusing force of faultless mistakes of fact to cases of faultless mistakes of morality. I conclude that an agent is morally blameworthy for his actions only if he believes that what he is doing is wrong, it is true that what he is doing is wrong, and his reasons for so believing properly identify the features of his actions that make them wrong.

When, if ever, is it rational for an agent to act morally? To fully answer such a question we must appeal to a theory of practical reason. My project is to defend one such theory by determining which features we most strongly associate with practical reason and then providing a theory which best accounts for those features. One of the chief features we associate with practical reason is that it has to do somehow with correct deliberation. Recognizing this feature leads theorists as diverse as Hobbes and Kant to accept what might be called the standard view: it is correct deliberation, and correct deliberation alone, which reveals an agent's reasons. I argue that the most prominent and plausible examples of the standard view fail to show that there is any moral requirement that is rationally required for every given agent. I then argue that the inability to connect rationality and morality in this way is a severe defect of the standard view. This is because another of the chief features we associate with practical reason is that the phrase 'what is rational' is nearly synonymous with endorsing phrases such as 'what makes sense' or 'what ought to be done'. I argue that in order to preserve this synonymy we must have a theory of rationality which is capable of saying it is always irrational to violate certain moral requirements; but, this is something the standard view cannot accommodate. I argue that the theory which best captures the various features we associate with practical reason is the virtue theory of practical reason. It says that an agent has reason to perform an action just in case there is a suitable deliberative connection between that action and some motive she would have were she to have a correct or virtuous set of motivations. I include in the dissertation a discussion of how we gain knowledge about this set of motivations. I also address various naturalistic worries that the virtue theory raises.

This essay addresses the use of intuitions as evidence in contemporary analytic philosophy. Chapter 1 demonstrates that intuitions are currently treated as the primary source of evidence in philosophical investigation. Chapter 2 defends an account of intuition on which an intuition that p involves p's seeming necessarily true. Chapter 3 takes up one broad strand of contemporary skepticism about the evidential value of intuitions. It outlines some contemporary arguments against the use of intuitions in moral philosophy, semantics, modal metaphysics, and epistemology. It concludes with an outline of the general argument form of which the particular arguments presented are instances. Chapter 4 explains why one contemporary attempt to meet this kind of skepticism fails, and then goes on to argue that the skeptical arguments fail because they are unsupported and self-defeating. Chapter 5 turns to a more general ground of skepticism about intuitions: the claim that we have no independent assurance of their reliability. Drawing on the work of Thomas Reid and William Alston, it shows that this fact cannot reasonably ground a skepticism restricted to intuition because the same is true of every one of our basic faculties.

There is something mysterious, and perhaps even dubious, about 'ought' claims. They seem to exert an authoritative power, a "binding force," over us. The norms of morality are most often said to exhibit such an authoritative force. The "queerness" of this alleged property has led many to moral skepticism. But, normative authority is no less mysterious in the case of the 'oughts' of epistemics, logic or prudence. The questions "Why should I believe the truth? accept deductive inferences? act prudently?" are puzzling in the same way as the more familiar worry "Why should I be moral?" Moral philosophers who have tried to explain the nature of normative authority have most frequently focused their efforts on developing theories of the nature of moral facts, our epistemic access to such facts, or our motivational responses to them. It seems to me that each of these approaches is inadequate to the task of capturing normative force. One may know that it is a fact that stealing is immoral but still wonder whether one should steal. One may feel a strong motivation to be honest without being convinced that there is good reason to be so motivated. We will not clear up the mystery of normative authority by clearing up the metaphysics, epistemology, or motivational efficacy of norms. I contend that normative authority is a matter of justification. A norm is authoritative for an agent if and only if it is justified in a thorough-going sense, which I refer to as "justification simpliciter." I analyze the nature of justification simpliciter by means of an extended analogy with epistemic justification. There is a regress problem with justification simpliciter, and there are foundationalist, coherentist and externalist approaches to solving that problem. I conclude that foundationalist and externalist models of justification simpliciter fail. I then develop a coherentist theory of the nature of normativity, called Reflective Endorsement Coherentism. According to this theory, an agent is justified in accepting norm N as a guide to her action if and only if she can both endorse N upon reflection and reflectively endorse her own practices of endorsement.

In recent decades "virtue ethics" has become an accepted theoretical structure for thinking about normative ethical principles. However, few contemporary virtue ethicists endorse the commitments of the first virtue theorists--the ancient Greeks, who developed their virtue theories within a commitment to eudaimonism. Why? I believe the objections of modern theorists boil down to concerns that eudaimonist theories cannot properly account for two prominent moral requirements on our treatment of others. First, we think that the interests and welfare of at least some others (e.g. family, friends, loved ones) ought to give us non-instrumental reason for acting--that is, reason independent of consideration of our own welfare. Second, we think others are entitled to what we might call respect, just in virtue of their being persons. Eudaimonist accounts (the objection runs) either cannot account for these intuitions at all, or they give the wrong sort of account. My dissertation assesses the resources of eudaimonism to meet these lines of criticism. Chapter 2, 3, and 4 survey the views of Plato, Aristotle, and the Stoics, to discover insights that are important for a successful response. In Chapters 5 and 6, I offer my own account, based on what I call empathic identification. This is the habit or disposition of seeing things, in effect, through the eyes of others. Empathic identification is a process through which the interpersonal transmission of reasons for actions between persons becomes possible. I argue first that our interest in our own eudaimonia justifies us in identifying empathically with others as a general habit or disposition. Second, I argue that empathic identification explains our intuitions about the respect others are due. So empathic identification generates the right sort of explanation of our intuitions about the constraints others and their interests impose upon us after all, and renders eudaimonist virtue ethics a viable form of ethical theory.

What do we mean when we say that a belief is justified? What justifies a belief? These are two very different questions. An answer to the first question is an attempt to offer a conceptual analysis of justification, an explication of the meaning of the term. An answer to the second question, on the other hand, is a substantive account of epistemic justification, a set of conditions under which a belief is justified. I argue that one's substantive account of a given notion should only be attempted after one has arrived at an analysis of that concept. After distinguishing between a conceptual analysis and a substantive account, I proceed to offer an analysis of the concept of epistemic justification. The analysis begins by noting three essential features of epistemic justification: truth, goal-directedness, and normativity; the correct analysis, then, must capture the relations between these components. I begin by discussing the relation between justification and truth, and argue that the two must be conceptually linked; specifically, the analysis of justification must invoke truth-directedness. I then undertake a discussion of rival theories of truth, as that debate importantly influences the project of epistemology. The analysis I ultimately offer is "Janus-faced"; it invokes normativity in two distinct ways. My hope is that this analysis will help guide us to the correct substantive account of epistemic justification; such is the goal of the larger project of which this dissertation is the first stage.

This thesis will argue that Plato's influential philosophical puzzle known as the Meno Paradox and the related Problem of False Belief are a more serious threat to Plato's philosophical programme (and ours) than many interpreters recognize. Furthermore, Plato's most obvious candidate for a solution to these problems, the Theory of Recollection, is not sufficient to explain how the Paradox misunderstands the epistemic processes of learning which it treats. This failure of Plato's account motivates a close consideration of Aristotle's sophisticated attempt to resolve the difficulties Plato raises. I will argue that a proper understanding of Aristotle's philosophy of mind and the forms of cognition through which he thinks humans progress yields the key to a powerful and heretofore unrecognized Aristotelian solution to the Meno Paradox and the Problem of False Belief.

In the last several years, a growing number of philosophers, including Thomas Hill, Jean Hampton, Neera Badhwar, and Robin Dillon, have turned their attention to the issue of self-respect. While several authors have identified a number of behaviors that are incompatible with self-respect, few have attempted an extended analysis of self-respect. Moreover, comparatively little attention has been focused on the moral importance of self-respect. In my dissertation, I build on the work of these and other philosophers. I begin by developing an analysis of self-respect. I argue that there are at least three distinct components of self-respect; specifically, a self-respecting person is true to herself, respects her interests and respects her judgment. I argue that no single component is sufficient for self-respect; for instance, a person who respects her judgment may yet fail to respect her interests. Similarly, a person who is true to herself does not necessarily fully respect either her interests or her judgment. In the remainder of my dissertation, I demonstrate why self-respect is so important for moral philosophy. Specifically, I focus on the moral issues that arise when a person who lacks self-respect interacts with others. I argue that a lack of self-respect may morally corrupt both the individual who lacks self-respect and those with whom she interacts. The danger of significant moral corruption is intensified in intimate relationships. Moreover, such corruption is not always confined to the relationship in which it was initially fostered. Exploitation is among the vices that thrive when individuals lack self-respect. In the final chapter, I demonstrate the relevance of self-respect to analyses of exploitation. For instance, Robert Goodin has argued that exploitation is impossible where all parties to a relationship have an equal stake in the relationship; this means that each party has as much to lose as any other should the relationship be terminated. I argue that persons who lack self-respect are vulnerable to exploitation even when they wield equal power in their relationships with others. That is, self-respect has an independent effect on a person's vulnerability to exploitation; a deficiency of self-respect is sufficient to render a person exploitable.

According to Boyd/Putnam, scientific realism is the view that successful theories are typically approximately true and that their key terms typically refer. The no-miracle argument for the view holds that approximate truth and reference provide the best explanation of the success of science. I try to defend scientific realism from the following six lines of antirealist objections. First, constructive empiricists argue that inference to the best explanation is a problematic rule of inference. I try to show that their critiques of inference to the best explanation backfire on van Fraassen's positive philosophical theories, such as the contextual theory of explanation and constructive empiricism. Second, pessimistic inducers argue that successful current theories will follow the fate of successful past theories which turned out to be completely false. I reply that realists can get around the historical objection, once they take the realist attitude only toward successful theories that cohere with each other. Third, antirealists from van Fraassen (1980) to Stanford (2000) have been proposing antirealist explanations of the success of science, thereby challenging the realist claim that the realist proposal is the best. I criticize eight antirealist proposals that I found in the literature with a view to proving that the realist proposal is still the best of the proposals I know of. Fourth, antirealists reject realism based on their views on the nature of scientific explanation. I critically evaluate four antirealist objections coming from that route. Fifth, antirealists might object that the key realist predicate, 'approximate truth,' is obscure. I reply that the predicate is viable, because there are clear cases of approximately true descriptions, and because Hilpinen/Lewis's theoretical account of approximate truth can handle those clear cases. Sixth, constructive empiricists claim that constructive empiricism is better than scientific realism because it explains science without extra epistemic risk. I attempt to prove, contrary to what the constructive empiricists believe, that empirical adequacy is harder to come by than approximate truth in the light of the pessimistic induction and the realist responses to it. Conclusion. Semantic, economic, empirical, and pragmatic considerations as a whole favor scientific realism over scientific antirealism, when realists believe that our best theories, successful theories that cohere with each other, are approximately true, and antirealists believe that they are approximately empirically adequate. Scientific realism is overall better than scientific antirealism.