The second-person approach advocated by Schilbach and colleagues may be seen as one of a group of theoretical approaches that avoid the “simulation theory” and “theory theory” horns of the dilemma of understanding other minds. Like other relational approaches (e.g., Barresi & Moore Reference Barresi and Moore1996; Carpendale & Lewis Reference Carpendale and Lewis2004; Hobson Reference Hobson2002; Moore Reference Moore2006; Zlatev et al. Reference Zlatev, Racine, Sinha and Itkonen2008), Schilbach et al. argue that minds are known within and through interaction with others. As a viable theory, however, their second-person approach has a number of significant drawbacks. Here we focus on two – its over-reliance on emotional engagement and its overemphasis of dyadic, rather than triadic, interaction. We believe that a significant reason for these shortcomings is that Schilbach et al. appear not to have a coherent account of what it means to understand mind; certainly they never actually define what that means. Obviously they want to avoid the standard representational theory of mind account of mental understanding. But instead of a structured analysis, they seem to assume that the understanding of mind is immanent in a variety of different social phenomena, including contingent social interaction and emotional reactivity to others.

Our position, consistent with a long intellectual tradition in philosophy of mind (e.g., Brentano Reference Brentano, Rancurello, Terrell and McAlister1874/1973), is that understanding mind entails understanding intentionality. We take intentionality to cover all of its myriad forms, ranging in complexity from simple object-directed action to complex embedded mental states (see Barresi & Moore Reference Barresi and Moore1996), and ranging across a variety of psychological qualities, including not only emotional, but also epistemic, and conative forms.

For Schilbach et al., there are two key features to the second-person approach: emotional engagement and social interaction. We address the limitations of these two features of their account in reverse order.

All relational approaches to social understanding place social interaction at the core. Knowledge of minds happens through interaction with others. For some authors, social interaction is seen primarily as the solution to the problem of other minds (e.g., Carpendale & Lewis Reference Carpendale and Lewis2004; Hobson Reference Hobson2002). For others, it is the solution not only to that problem, but also necessarily to the problem of how the self's own intentionality comes to be known (Barresi & Moore Reference Barresi and Moore1996). Schilbach et al. argue for the primacy of a particular form of social interaction – face-to-face or what is often termed in the developmental psychology literature, “dyadic.” For them, second-person appears to mean primarily the kind of social stimulation available within dyadic interaction. Certainly dyadic interactions can have special dynamic properties, such as contingency of the actions of self and other, and particular characteristics, such as full-face gaze. Yet, although it is true that these properties and characteristics are key attractants to young infants, the processing of this information does not necessitate any awareness of the other as being another – or being a person of the same kind as the self. Indeed, empirical evidence has suggested that these phenomena could be subserved by “subpersonal” attentional and sensorimotor mechanisms (Moore & Barresi Reference Moore, Barresi, Zelazo, Chandler and Crone2009; Paulus Reference Paulus2011).

The same problem holds for their view on motor resonance in the Mirror Neuron System when observing others' actions. While we agree that these motor processes may support social interaction either by predicting the future effect of the other's action or by directly preparing a timely response, the activation of a motor program alone need not lead to an awareness of another's mind in any conceptual sense (Paulus Reference Paulus2012). There is a conceptual gap between the activation of one's own motor system through the perception of another person's action and the ascription of an intention to this person or to the self (Jacob Reference Jacob2009).

The problem with purely dyadic interactions is that there is no obvious way for the intentionality of action – its object-directedness – to be manifest. That is, it is unclear how the properties of dyadic interactions alone, such as contingency and second person characteristics, could reveal intentionality at all. Intentionality is tied inextricably to actions on objects, whether real or represented, and therefore to triadic interaction. Triadic interaction involves participation in joint or coordinated actions over shared objects, often directed at particular effects (Paulus et al. Reference Paulus, Hunnius and Bekkering2012) and it is through participation in these interactions that the activity of both self and other becomes interpretable as intentional (Moore Reference Moore2006; Tomasello et al. Reference Tomasello, Carpenter, Call, Behne and Moll2005). Therefore, while we agree with Schilbach et al. that dyadic interaction is a necessary context for intentional understanding, we argue that it cannot be sufficient.

Schilbach et al. reserve a place of particular importance in their theory for emotional engagement. We agree that emotional engagement is of critical importance, particularly during early development, for bringing people into the kinds of interactive situations that will ultimately enable intentional understanding. However, intentionality involves much more than emotion. Interactive partners engage in other forms of coordinated activity where emotion may play a relatively minimal role. Two broad forms of coordinated activity involve shared epistemic relations to objects and shared conative relations to objects or goals. By epistemic relations, we mean psychological activity that is directed at the acquisition, elaboration, and negotiation of knowledge. Shared epistemic activity, such as joint attention, can deliver an understanding of epistemic mental activity that will elude purely emotional engagement, such as the understanding of perspective and belief. By conative activity, we mean activity that is willed, purposeful, and goal-directed. Shared conative activity, such as imitation and cooperation involving joint goals, provides an entry into the understanding of goal-directed actions and desires. Emotional interaction on its own is not well-suited to the acquisition of an understanding of either epistemic or conative types of intentional relations.

In short, although we applaud Schilbach et al.'s attempt to set the neuroscience of social understanding in a context that places social interaction as the foundation, we believe that their account must be elaborated to show how interaction beyond emotional engagement can yield the key understanding of mind as intentional.