My work in philosophy began with questions about the force of moral or other practical reasons. Serious moral reasons seem to tell us what we "must" do. More generally, in cases where we act on reasons, we speak of them as "making" us act. My first published article addressed such questions in terms of the logic of ought-judgments, arguing that facts about an agent's desires or intentions don't allow for "detachment" of ought-judgments requiring action, but only for conditional judgments on the order of : "If I want to do x, I ought to do y." This is essentially a version of Kant's insistence on a "categorical imperative," an "ought" that holds for all agents whatever they happen to want. It means that instrumental or means/ends ought-judgments can't be enough by themselves to yield reasons that actually have force for action unless we add some further assumptions about something the agent can't "undo" in the way that she might be able to modify her desires.
However, though I wanted to capture some of the insights of a Kantian approach to ethics and practical reasoning, my own inclinations in philosophy are basically in the "naturalist" camp - essentially the approach that understands ethics on the basis of categories shared with the sciences. So I wasn't happy with a treatment of reasons unless it connected with psychological motives for action. In an attempt to supply a factor that explains the motivational force of moral and other reasons, I began a long-running project on emotions - a subject that turned out to be fascinating in its own right, with connections to a number of other areas of philosophical interest, including free will and responsibility.
Some of my articles during this period deal with current issues such as those raised by research on genetic causes of crime. However, my primary output consisted in two books for philosophers, Emotions and Reasons and Practical Guilt. The first works out an account of emotions and of what makes emotions rationally appropriate or inappropriate; the second applies the account to questions about the role of emotion in the bases of ethics, with a focus on issues raised by moral dilemmas - cases where, through no fault of her own, all the alternatives open to an agent turn out to be wrong. More recently, I've written some short pieces on morally significant features of persons and interpersonal relationships that raise general questions about autonomy and reasons for action, questions of the sort that initially sparked my interest in "moral psychology" (as the general field that covers all these issues is now called).
I now mainly write retrospective or "offshoot" articles on these subjects for conferences, often interdisciplinary conferences bringing philosophy to bear on other areas, including psychology, cultural studies, medicine, and the law. In my current project, however, I'm returning to a direct focus on questions about the force of reasons. But the approach is now less abstract, with an attempt to supplement work on the logic of reasons with a general view of emotional motivation and the role of emotions in moral development. I take emotions to have cognitive as well as affective content, so that they can be seen as reinforcing moral and other reasons for action, or practical reasons, with an element of feeling that supplies a further practical reason besides the evaluative element that is the focus of the agent's attention. In a case of anger, say, the evaluative element would amount to something like the thought that the agent has yet to retaliate for a slight to herself or to someone else she cares about -- as Aristotle says, though he also represents the evaluative element as accompanied by pain. My own version essentially adds an affective element that supplies a further reason for taking action -- in order to sustain or alleviate emotional comfort or discomfort at what's given in the evaluative element. This allows for indirect strategies of emotional self-management - for instance, working up indignation to get oneself to face down an unresponsive clerk in a store, along with other cases where just knowing that one ought to do something might not supply enough motivation for effective action. Such strategies involve a modicum of control over emotions, in contrast to the usual picture of emotions as simply coming over us willy-nilly.
The motivational force of moral reasons needn't depend on variants of anger, of course, but rather, for instance, anticipatory regret and related attitudes of blame or reproach -- not necessarily full-blooded emotions, but just the kind of uneasiness about an act that provides a reinforcing reason against it besides what's given in the evaluation of it as unwise or wrong. The aim of my current project, insofar as it bears on emotions, is to construct an intermediate view between two opposing camps in recent debate: those that interpret practical reasons as themselves subjective states of the agent (typically desire and belief) and those that take reasons as objective facts whose recognition by a rational agent would necessarily be enough to motivate her to act. Instead I take reasons as critical assessments of action, capable of being encoded in an emotion or other motivating attitude, whether or not they require action as a condition of rationality.
Apart from its bearing on emotions, the point of the work I'm doing now is to correct a somewhat inflated view of reasons that some philosophers hold. Some attempts to explain morality as required by practical rationality make out reasons in general as considerations a rational agent *has* to act on. I instead defend a notion of rationality favored by some other current authors as leaving room for a choice among options, even where one of them is assumed to be the best. What I hope to add is a less simplistic understanding of the sense in which rational agents are motivated by reasons when they are so motivated. In the effort to explain the moral "must," I think we need to move beyond the rationality of individual agents to notions of social coordination and the requirements of social life - essentially, social rationality - but with a road back into individual motivation supplied by the link to emotions. Some of these ideas began to emerge in my book on guilt, which focused primarily on the issue of moral dilemmas. In my current project, "Practical Reasons and Moral 'Ought'," I expect to put the more general issues about practical rationality and metaethics into center stage.