by Stephen A. Butterfill
How could we come to know that another is angry about an obstacle she has encountered, or that she is happy about an outcome? Some such knowledge is uncontroversially acquired by inference. However, some philosophers have recently defended the hypothesis that knowledge of others' anger or joy might be acquired by perceiving it (e.g. Smith, 2010; McNeill, 2012a,b). In the first part of this talk I offer a challenge to the view that humans can perceive anger or joy in the same sense that they can perceive shapes or textures. The challenge is to specify a model of anger and other mental states which captures how these mental states appear to the perceivers. This is a hard challenge to meet because available models arguably render mental states imperceptible. In the second part of the talk I propose an alternative way in which knowledge of others' mental states could be acquired, one that hinges on interaction rather than perception or inference. Reflection on what is involved in sharing a smile suggests that one route to knowledge of others' mental states might involve interacting with them.