In some cases the self can be better modeled as competing agents.
Thomas Schelling, a Nobel prize-winning economist, was also for much of his life an inveterate smoker. Searching for ways to quit, Schelling applied game theory—a science concerned with strategic interactions—to his problem. Schelling identified his quest to quit smoking as being like a two-player game—in which he was both players. He was the smoker; and he was the person desperate to quit and lead a healthier life. pdf