  Carolyn Morillo has also defended a pleasure-based theory of desire, though on quite different grounds. Beginning on conceptual grounds, Morillo argues that desires are ontologically independent of action, because they are non-trivial explainers of action. And then on empirical (specifically, neuroscientific) grounds, Morillo argues that episodes of pleasure are identical to certain neural events (the release of dopamine by what is known as the ‘reward system’), and these same neural events are the causal origin (in conjunction with belief) of action. Thus, episodes of pleasure play the role of desires, and so desires are episodes of pleasure (Morillo 1990).