 Neurophilosophy continued to apply findings from the neurosciences to traditional, philosophical questions. Examples include: What is an emotion? (Prinz 2004) What is the nature of desire? (Schroeder 2004) How is social cognition made possible? (Goldman 2006) What is the neural basis of moral cognition? (Prinz 2007) What is the neural basis of happiness? (Flanagan 2009) Neurophilosophical answers to these questions are constrained by what neuroscience reveals about nervous systems. For example, in his book Three Faces of Desire, Timothy Schroeder (2004) argued that our commonsense conception of desire attributes to it three capacities: (1) the capacity to reinforce behavior when satisfied, (2) the capacity to motivate behavior, and (3) the capacity to determine sources of pleasure. Based on evidence from the literature on dopamine function and reinforcement learning theory, Schroeder argued that reward processing is the basis for all three capacities. Thus, reward is the essence of desire.