Commonsense morality and not being required to maximize the overall good

On commonsense morality, there are two types of situations where an agent is not required to maximize the impersonal good. First, there are those situations where the agent is prohibited from doing so--constraints. Second, there are those situations where the agent is permitted to do so but also has the option of doing something else--options. I argue that there are three possible explanations for the absence of a moral requirement to maximize the impersonal good and that the commonsense moralist must appeal to all three in order to account for the vast array of constraints and options we take there be.