There is a body of commonsense knowledge about human psychology that we all draw upon in everyday life to interpret our own actions and those of the people around us. In this paper,we define a logic in which this knowledge can be expressed. W e focus on a cluster of emotions,including approval, disapproval, guilt, and anger, most of which involve some sort of ethical evaluation of the action that triggers them. As a result, we are able to draw on well-studied concepts from deontic logic, such as obligation, prohibition, and permission. W e formalize a portion of commonsense psychology and show how a simple problem can be solved using our logic.