Christine Marion Korsgaard

Life and Academic Career

Christine Marion Korsgaard (born 9 April 1952) is an American philosopher widely regarded as one of the leading contemporary exponents of Kantian ethics. Raised in Chicago, she studied philosophy at the University of Illinois at Urbana–Champaign and went on to complete her PhD at Harvard University under the supervision of John Rawls, a connection that situates her within the broader Rawlsian and neo-Kantian revival in late 20th‑century Anglophone philosophy.

Korsgaard taught at Yale University and the University of Chicago before returning to Harvard, where she became the Arthur Kingsley Porter Professor of Philosophy. Over several decades she has been a central figure in debates about practical reason, metaethics, and moral psychology, and her work has been influential across both analytic and broadly Kantian traditions.

Her major books include Creating the Kingdom of Ends (1996), The Sources of Normativity (1996), Self-Constitution: Agency, Identity, and Integrity (2009), and Fellow Creatures: Our Obligations to the Other Animals (2018). These works develop a systematic view that spans the foundations of morality, the nature of agency, and questions about the moral standing of non-human animals.

Kantian Constructivism and Normativity

Korsgaard is best known for her defense of Kantian constructivism in metaethics, especially as articulated in The Sources of Normativity. The guiding problem of this work is what she calls the “normative question”: what justifies the authority of moral and practical obligations over us?

Against moral realism, which holds that moral truths are independent normative facts or properties, Korsgaard argues that such facts would be “normatively inert” unless they could be connected to the standpoint of an agent who must act. At the same time, she rejects simple subjectivism or relativism, which appear unable to account for the genuine authority and apparent objectivity of moral claims.

Her central proposal is that normativity is grounded in the reflective structure of human agency:

• Human beings are reflective agents: when we are prompted to act by desires or impulses, we do not simply act; we can step back and ask whether we ought to act on a given motive.
• In deciding what to do, we must adopt principles or maxims that we can endorse as reasons. These principles express our practical identity—the roles, projects, and values in terms of which we understand ourselves.
• To act at all as a unified, self-governing agent, we must regard ourselves as bound by certain norms that structure our will. In committing ourselves to these norms, we in effect “legislate” principles for ourselves as rational agents.

This yields a form of constructivism: normative truths are not discovered as independent moral facts, but are constructed from the point of view of rational agents deliberating under constraints internal to agency itself. However, Korsgaard maintains that this standpoint is not arbitrary or purely individual. Because we must see ourselves as members of a community of rational beings, the principles to which we are committed must be universalizable and publicly justifiable, echoing Kant’s Formula of Universal Law and Formula of Humanity.

Supporters of Korsgaard’s approach argue that it explains why moral requirements have practical authority: they arise from what we are as agents who must act for reasons. Critics contend that her account is either too weak (collapsing into a sophisticated subjectivism if agents can choose their identities too freely) or too strong (smuggling in robustly moral assumptions—such as the equal importance of all rational agents—that she claims to derive from the structure of agency alone).

Personal Identity and Practical Identity

Another central theme in Korsgaard’s work is the nature of personal identity and its relation to morality. In her influential essay “Personal Identity and the Unity of Agency,” and later in Self-Constitution, she argues that questions about who we are cannot be adequately addressed purely in metaphysical terms of continuity of body or stream of consciousness.

Instead, she emphasizes practical identity: the ensemble of commitments, roles, and values through which a person understands herself as an agent. Being a parent, a citizen, a friend, or a moral agent are examples of such identities. Korsgaard argues:

• To act rationally is to “constitute” yourself as a certain kind of agent by endorsing and acting on reasons that reflect your practical identities.
• Agency requires unity of the self over time; this unity is achieved through self-constitution, in which we shape our lives according to principles that we can regard as expressive of a coherent identity.
• Acting against one’s deepest commitments, or in ways that attack one’s own integrity, is a form of practical self-destruction, undermining the unity of the agent.

On this view, personal identity is not merely something we discover; it is something we actively maintain and construct by living in accordance with certain standards. Ethical failure is not only a failure relative to external norms, but also a failure to be a unified agent.

Some philosophers have welcomed this connection between agency, identity, and normativity as illuminating both ethics and the philosophy of action. Others argue that Korsgaard’s notion of practical identity risks circularity: if our most fundamental identity is that of a moral agent, then the appeal to identity may presuppose the very moral norms it is meant to ground. There is also debate over whether all rational agency must take the form she describes or whether a more fragmented, less unified kind of agency is conceptually possible.

Animals, Ethical Theory, and Legacy

In Fellow Creatures: Our Obligations to the Other Animals, Korsgaard extends her Kantian constructivism to address the moral status of non-human animals. Traditional Kantian ethics has often been criticized for treating animals as having only indirect moral standing—valuable merely in relation to human ends. Korsgaard challenges this interpretation and argues that a properly Kantian perspective supports robust obligations to animals.

Her key claims include:

• Animals, like humans, are conscious subjects of a life; they have experiences that matter to them, including pleasure, pain, and various forms of flourishing.
• Although many animals may not be capable of reflective endorsement of reasons in the human sense, they are still teleological beings who pursue ends grounded in their own good.
• From the standpoint of a rational agent committed to universal principles of justification, one cannot coherently deny that such beings have moral claims. To treat the comparable interests of animals as simply negligible would be to adopt principles that could not be justified from an impartial perspective.

Korsgaard thus argues for a strong form of moral consideration for animals, often drawing conclusions that converge with those of utilitarian theorists like Peter Singer, while maintaining a distinctively Kantian, non-consequentialist foundation. Proponents see this as a major contribution to animal ethics, showing how duties to animals can arise from a broadly deontological framework. Critics question whether her account stretches the Kantian notions of autonomy and rational agency beyond their original scope, or whether it fully escapes anthropocentric assumptions.

Across her work, Korsgaard has played a central role in reshaping contemporary debates about normativity, agency, and moral status. Her interpretation of Kant has influenced discussions of practical reason in both moral and political philosophy, and her arguments have become standard reference points in metaethics, especially in discussions of constructivism. Regardless of one’s evaluation of her conclusions, her systematic attempt to show how morality arises from the conditions of agency itself has made her one of the most widely discussed moral philosophers of the late 20th and early 21st centuries.