Two main types of philosophical arguments have been given in support of the claim that the citizens of affluent societies have stringent moral duties to aid the global poor: “positive duty” arguments based on the notion of beneficence and “negative duty” arguments based on noninterference. Peter Singer’s positive duty argument (Singer 1972) and Thomas Pogge’s negative duty argument (Pogge 2002) are among the most prominent examples. Philosophers have made speculative claims about the relative effectiveness of these arguments in promoting attitudes (...) and behaviors that could lead to the alleviation of poverty. In this article we present the results of two empirical studies that evaluate these claims, and suggest that both arguments have a modest effect on people’s attitudes and behaviors regarding global poverty. In a replication of the second study, the negative duty argument, in particular, had a statistically significant effect on donations. We discuss the theoretical and practical significance of these results and suggest directions for further research on the role that philosophical arguments can play in engendering concern and action on pressing moral problems. (shrink)