Abstract: How does one best go about understanding the actions of other people? According to what I shall call the ‘rationalist` line, we start by assuming that the beliefs and desires of others form a rational set. The basis for this assumption, as found in the work of Donald Davidson and as recounted here in this paper in the writings of Brian Fay and Jaegwon Kim, is that without such an assumption it is impossible to attribute to people beliefs. On this theoretical basis, it is then suggested that our strategy in interpreting others should proceed by either ‘simulating` their cognitive situations or by theorizing about their situations in terms of folk psychology. In either case, the goal of the investigation is to preserve the rationality of the agent. My goal is to criticize the rationalist line. I argue, first, that it is incomplete. For it fails to take into account the impact of social forces that often act sub-consciously on people (a classic example is Durkheim`s notion of ‘anomie`). Moreover, it fails to recognize the role of practical knowledge (practical skill) in people`s actions. Secondly, I argue that rationalism suffers from indeterminacy in that it is occasionally at a loss in assessing whether an agent is rational. It turns out that supplying the further detail that solves this indeterminacy leads to a consideration of various empirical factors, factors that prompt us to challenge the rationalist line.