Tort law has long distinguished between misfeasance, which is accompanied by a duty of care, and nonfeasance, which is generally not. Thus a driver has a duty to brake for a pedestrian in the street, but a bystander has no duty to rescue him. Only in rare cases do parties like the bystander have an “affirmative” duty to exercise reasonable care. But the idea of affirmative duty has done more harm than good. The doctrinal treatments of nonfeasance and affirmative duties too often encompass situations that could just as easily be considered regular misfeasance cases. This, we argue, is because even textbook illustrations of misfeasance and nonfeasance reveal little real distinction between the two. In effect, there is no such thing as affirmative duty, as tort law uses that term. This article’s primary objective is to show that this is the case and explain why it is so. We reveal the descriptive and normative confusion surrounding the concept of affirmative duty. We explain the sources of this confusion, both conceptual and historical. And we begin the project of reconstructing existing law on a firmer conceptual footing. As it turns out, this does not involve the categories historically relied on by tort law. Instead, these categories contain within them other factors that help to define the scope of liability. In the end, ideas such as misfeasance and nonfeasance, and regular duties and “affirmative” duties, are largely beside the point.