What Imagine a group of strangers who witness a violent assault. Each of the strangers implicitly understands that they alone cannot help the victim, but that they are jointly capable of stopping the assault. In such a case, each of the strangers has an experience of shared responsibility, although they are helpless as individuals. This everyday case poses some serious questions about moral agency. In which sense are unstructured associations moral agents? This research project explores this question by carrying out a phenomenological analysis of shared ethical demands. It aims to elucidate the interplay between agency, intersubjectivity, and normativity that characterizes moral agency and makes shared responsibility possible. Why Current research in philosophical ethics ascribes responsibility to individuals (individual responsibility) and to well-defined groups (collective responsibility) but lacks a concept of shared responsibility, that is, the responsibility of unstructured associations. While under-theorized, the experience of shared responsibility holds an important place in our ethical lives. We often feel that “we,” on the one hand, ought to do something that exceeds our capacities as individuals, when “we,” on the other hand, are not united in a well-formed (e.g. legally liable) group. Without an adequate concept of shared responsibility, we cannot make sense of this ethical phenomenon, and we overlook an important motivating factor in our everyday actions and moral dilemmas. How I will analyse the experience of shared ethical demands in terms of (1) its action-theoretic presuppositions (our experience of what can be done), (2) its specific type of intersubjectivity (our experience of who is called to action), and (3) its normative consequences for the way in which we evaluate the behaviour of ourselves and others (our experience of being morally tainted). Methodologically, the project provides a novel contribution to the current discussion of collective responsibility in analytical philosophy by drawing on insights developed by phenomenological philosophers like Heidegger, Merleau-Ponty, Løgstrup, Levinas, and Waldenfels. SSR Conceptualizing shared responsibility is important beyond academic and philosophical debates. The concept of shared responsibility clarifies some of the basic structures and processes that compel individuals with no prior relation to join together in order to prevent and remedy harm. In this way, it helps us understand and motivate joint moral action. This can be utilized strategically in NGO-settings and, more generally, to secure social cohesion among strangers. Without this concept, we cannot say why we should act when the success of our actions depends on the uncoordinated actions of others, and we cannot explain why we feel bad if we fail.