Date of Degree


Document Type


Degree Name





Sibyl A Schwarzenbach

Committee Members

Steven Ross

Sibyl Schwarzenbach

Jonathan Jacobs

Subject Categories

Ethics and Political Philosophy


Scanlon, contractualism, constructivism, reasonable rejection


This dissertation examines whether Thomas Scanlon’s contractualism satisfactorily explains its intended domain of morality which he terms “what we owe to each other.” Scanlon proposes that such interpersonal morality is based on justifying one’s actions to others by behaving according to principles that could not be reasonably rejected. This idea accounts for two key functions of a moral theory: explaining how moral judgments are made and why agents generally act according to these judgments. After reviewing the nature of constructivist moral theories to show why I chose to focus on Scanlon’s theory, I assess how effectively it fulfills these two roles. I argue that the concept of justifiability is necessary for making moral judgments because it enables agents to determine which of an action’s attributes are morally relevant and to choose between conflicting principles. However, I also argue that the contractualist procedure is unable to specify principles in certain cases where the aggregation of harms across multiple persons legitimately outweighs an individual’s concerns and in other cases where differences in agents’ experiences and sensibilities lead to conflicting moral judgments and objectionable relativism. Regarding normativity, I argue that justifiability provides sufficient reason for agents to act in accordance with these principles in most, but not all, cases, even if the agents are not motivated by the contractualist goal of finding common principles. In summary, I conclude that contractualism provides an insightful account of morality, but it is one with several significant defects that cannot be remedied.