Nussbaum vs Sen: How Their Capability Approaches Differ

Nussbaum vs Sen: comparison table

The table highlights a difference in degree of specification, not a complete opposition. Nussbaum and Sen remain close on the importance of real human freedoms, but Nussbaum gives philosophical theory a more substantial role in identifying minimum requirements of justice.

What is the Capability Approach?

The Capability Approach is a framework for evaluating human well-being, inequality and development by asking what people are genuinely able to do and to be. Instead of judging a person's situation only by income, wealth, utility or the resources formally available to them, the approach asks whether those resources actually give the person meaningful opportunities.

Amartya Sen was the major pioneer of the capability approach in economics and social philosophy, while Martha Nussbaum developed a closely related philosophical version with a stronger account of basic human entitlements and dignity. Both argue that resources alone are insufficient because people differ in their ability to convert resources into valuable ways of living.

For example, two people may receive the same amount of income, but one may live in a society with accessible healthcare and safe transportation while the other faces discrimination, disability-related barriers or political restrictions. Their resources may look similar on paper while their actual freedoms are very different.

The Capability Approach therefore shifts attention from what people possess to what genuine opportunities they have. For a broader introduction, see our Capabilities Approach guide.

What do Nussbaum and Sen share?

Nussbaum and Sen share the fundamental insight that the quality of a human life cannot be adequately measured by money, commodities or subjective satisfaction alone. They both focus on people's capabilities and functionings: capabilities concern the genuine opportunities a person has, while functionings concern the actual states and activities they achieve, such as being adequately nourished, being educated or participating in political life.

Both thinkers also emphasize that people convert resources into opportunities differently. Disability, gender discrimination, social norms, age, health and political institutions can affect what a person is actually able to achieve. This makes the capability perspective particularly useful for analyzing inequalities that conventional economic indicators can hide.

The relationship between the two thinkers is also historical rather than merely theoretical. Nussbaum and Sen worked together and co-edited The Quality of Life (1993). Their approaches subsequently developed in somewhat different directions, especially concerning the role of philosophical specification and the question of whether a capability list should be fixed.

What is Sen's Capability Approach?

Sen's capability approach evaluates well-being and advantage in terms of the freedoms people have to achieve valuable functionings. A functioning might be being adequately nourished, being literate, taking part in community life or appearing in public without shame. A capability is the person's real opportunity to achieve such functionings.

This distinction allows Sen to separate freedom to choose from the particular outcome chosen. Two people might both have the capability to fast, for example, but one may fast because of religious commitment while another is unable to obtain food. Looking only at the functioning—"both are not eating"—would miss the difference in freedom.

Sen also places considerable emphasis on agency. People are not merely recipients of welfare; they are agents who pursue goals and values. A person's agency can include activities that do not directly increase their own personal well-being, such as working for political reform or helping other people.

Another important feature of Sen's approach is its connection to comparative justice. In The Idea of Justice (2009), Sen argues that we do not always need to identify a perfectly just society before we can determine that one social arrangement is better than another. Reducing a clear injustice can be worthwhile even when disagreement remains about what a perfectly just society would look like.

What is Nussbaum's Capability Approach?

Nussbaum adopts the capability framework but gives it a more explicitly normative and constitutional structure. She argues that a theory of justice needs to identify certain central opportunities that every person should have at least to a minimum threshold.

Her influential formulation contains ten central capabilities: life; bodily health; bodily integrity; senses, imagination and thought; emotions; practical reason; affiliation; other species; play; and control over one's political and material environment.

Nussbaum does not claim that everyone must achieve identical outcomes in these areas. The concern is whether people possess sufficient genuine opportunities. A person may choose not to participate in politics, for example, but a just society should still protect the capability to participate.

Her approach is therefore closely connected to the idea of human dignity. Below a certain threshold, she argues, a person is deprived of opportunities so central to human flourishing that the situation should count as a matter of justice rather than merely unfortunate inequality.

Nussbaum describes her theory as a partial theory of justice. It does not attempt to settle every question about the ideal distribution of wealth or resources. Instead, it identifies a minimum level of central capabilities that political institutions should secure for everyone.

Why does Nussbaum support a fixed list?

Nussbaum believes that a theory of justice needs enough substantive content to say that some forms of deprivation are unacceptable regardless of whether a society has become accustomed to them. Her list of ten central capabilities is intended to provide that content.

Without some account of basic entitlements, she worries that a theory can become too dependent on existing preferences or political majorities. A society might accept severe restrictions on women's education or political participation, for example, while claiming that such arrangements reflect local values. Nussbaum's approach provides an external normative basis for criticizing those arrangements.

The list also gives her theory practical relevance for constitutional politics. Governments and courts can ask whether citizens have genuine access to the central capabilities rather than merely whether formal rights exist. The list therefore functions as a threshold of minimum justice, not as a demand that every person live in exactly the same way.

Why does Sen resist a canonical list?

Sen's objection is not that capabilities are impossible to identify or that no capability can ever be important. His concern is with establishing a single authoritative list of capabilities in advance and treating that list as the definitive content of justice across contexts.

Sen argues that different evaluative exercises can legitimately require different selections of capabilities. What matters for measuring poverty may not be identical to what matters for assessing gender inequality, democratic participation or environmental policy. Public reasoning can help determine which dimensions deserve attention in a particular context.

This position also reflects Sen's concern with democratic agency. If citizens are capable of discussing and evaluating the values that should guide their society, a philosopher should be cautious about deciding those values entirely on their behalf. Public reasoning allows affected people to participate in determining what should count as an important deprivation.

Sen's position therefore should not be summarized as "Sen has no list." A more accurate formulation is that he rejects the need for a single canonical list fixed by philosophical authority.

How do their ideas of justice differ?

Their disagreement about the list is connected to a broader difference in their theories of justice. Nussbaum is willing to specify substantive principles that should be treated as fundamental entitlements. Sen is more interested in using the capability perspective to identify and compare actual injustices without constructing a complete blueprint of an ideally just society.

In The Idea of Justice, Sen distinguishes his approach from what he calls a more transcendental search for perfectly just institutions. He argues that practical reasoning can compare existing alternatives even when people disagree about the complete structure of an ideal society.

Nussbaum's position is more institutionally demanding. Her threshold of central capabilities gives governments a substantive target: certain basic opportunities should be secured for every person. This makes her approach particularly suitable for discussions of constitutional rights and minimum standards of justice.

The difference can therefore be expressed as follows: Nussbaum asks what everyone must be guaranteed, while Sen asks how we can reason about and compare people's actual freedoms and injustices. The distinction is not absolute, but it captures an important difference in emphasis.

How do they understand freedom and agency?

Both thinkers treat freedom as more than the formal absence of government interference. What matters is whether people possess real opportunities to pursue valuable ways of living.

Sen places especially strong emphasis on agency. A person should be understood as someone who can pursue goals and participate in shaping their own life and society. Agency can therefore extend beyond personal welfare: people may choose to devote themselves to political causes, family responsibilities or the interests of others.

Nussbaum also values choice and agency, but places greater emphasis on securing a substantive minimum of central opportunities. Her concern is that people cannot meaningfully exercise freedom when basic capabilities have fallen below a threshold—for example, when severe violence, hunger or political exclusion prevents them from developing and exercising their human powers.

The approaches thus overlap substantially while giving different weight to agency, substantive guarantees and the role of political institutions.

Why is human dignity more central to Nussbaum?

Nussbaum's version of the Capability Approach is explicitly grounded in the idea that every person possesses a form of human dignity that political institutions must respect. The ten central capabilities identify areas of human life that she considers sufficiently fundamental that falling below a certain threshold constitutes a serious injustice.

This provides Nussbaum with a basis for making strong cross-cultural judgments. A practice cannot be defended merely by saying that it is traditional if it deprives people of capabilities that justice requires them to possess. This is particularly important in her work on women's rights, disability and global justice.

Sen shares the concern for human freedom and well-being but is less inclined to derive a universal list from a single philosophical account of human flourishing. His emphasis on public reasoning makes the determination of priorities more open-ended and context-sensitive.

Why is public reasoning important to Sen?

Public reasoning is central to Sen's account because judgments about justice should be open to discussion, criticism and revision. People should have opportunities to argue about what counts as deprivation, which inequalities matter and which policies would improve people's lives.

This emphasis connects the Capability Approach to democracy. Sen does not treat democratic institutions simply as mechanisms for choosing leaders. Public discussion can also improve the quality of social judgments by allowing different experiences and perspectives to challenge one another.

Nussbaum also values democratic deliberation, but she does not think public agreement alone can determine the basic requirements of justice. If a majority denies a minority access to a fundamental capability, Nussbaum's theory provides a basis for criticizing that decision even if it has democratic support.

The contrast is therefore between public determination of priorities and philosophically specified minimum entitlements. Both approaches value democratic reasoning, but they give it different normative roles.

How are their approaches used in development?

Sen's work has had an especially strong influence on the modern understanding of human development. His capability perspective helped shift attention away from economic growth alone toward people's health, education, freedoms and opportunities. The broader human development tradition associated with the UNDP Human Development Reports reflects this shift, although the Human Development Index is not simply a direct measurement of Sen's complete capability framework.

Nussbaum's approach has been particularly influential in philosophical discussions of constitutional rights, gender justice, education, disability and human dignity. Her list provides a more explicit normative framework for asking whether governments have secured minimum opportunities for citizens.

The distinction is useful in policy analysis. Sen's framework can help identify and compare different dimensions of disadvantage without requiring one universally fixed ranking, while Nussbaum's framework can provide a stronger basis for arguing that certain minimum capabilities should be protected as matters of justice.

What did Nussbaum and Sen actually disagree about?

Their disagreement became especially explicit in an exchange published in Feminist Economics. Nussbaum's "Capabilities as Fundamental Entitlements: Sen and Social Justice" (2003) defended a more specified account of capabilities and argued for treating central capabilities as fundamental entitlements. Sen responded with "Capabilities, Lists, and Public Reason: Continuing the Conversation" (2004).

The exchange is important because it shows that their disagreement was not about whether capabilities matter. Both accepted the basic framework. The question was how much philosophical determination should enter the selection and ranking of capabilities.

Nussbaum worried that leaving the content too open could make the theory insufficiently critical of injustice. Sen worried that a philosopher-provided list could become overly authoritative and insufficiently responsive to democratic reasoning and contextual differences.

The exchange is therefore best understood as an argument about the architecture of a theory of justice: should a capability approach provide a substantive list of fundamental entitlements, or should it primarily provide a framework within which people can reason about justice for themselves?

What are the strengths and criticisms of each approach?

Both approaches solve problems that the other approach can leave more exposed. Nussbaum's stronger specification gives her theory clear normative force, while Sen's openness gives his framework greater flexibility across different contexts and forms of public reasoning.

• Strength of Nussbaum's approach: The ten capabilities provide a clear standard for identifying severe deprivation and criticizing social practices that violate basic human opportunities.
• Criticism of Nussbaum: Critics can question who has the authority to determine a universal list and whether a single list can adequately reflect different cultures, circumstances and reasonable disagreements.
• Strength of Sen's approach: Public reasoning makes the framework adaptable and gives citizens a role in determining which capabilities and inequalities deserve priority.
• Criticism of Sen: If the framework does not specify enough substantive standards, critics worry that it may become difficult to identify which deprivations should count as fundamental injustices.
• Shared challenge: Both approaches must explain how capabilities should actually be measured and compared in real societies, especially when capabilities involve complex freedoms that cannot easily be reduced to a single number.

The disagreement therefore reflects a broader tension in political philosophy between normative specification and democratic openness. Too little specification can make a theory vague; too much specification can make it appear paternalistic or insufficiently responsive to disagreement.

Why does the Nussbaum–Sen disagreement matter?

The disagreement matters because it raises a fundamental question about what political philosophy should contribute to debates about justice. Should philosophers identify substantive principles that governments must respect, or should they provide conceptual tools that citizens can use through democratic reasoning?

Nussbaum's answer is that some basic human opportunities are too important to leave entirely to political negotiation. Her ten capabilities establish a minimum floor below which human dignity is compromised. Sen's answer is more open-ended: democratic societies should use public reasoning to determine relevant values and compare actual alternatives rather than relying on a philosopher's definitive blueprint.

Their disagreement also shows why the Capability Approach is broader than a simple measure of income or happiness. It asks us to examine the actual freedoms people possess and the social conditions that shape those freedoms. This makes it relevant to poverty, gender inequality, disability, education, health, political participation and development.

Ultimately, Nussbaum and Sen can be seen less as opponents than as thinkers who pushed the same basic insight in different directions. Sen emphasizes the openness of democratic evaluation; Nussbaum emphasizes the moral necessity of securing certain central human capabilities. Understanding both makes the Capability Approach considerably richer than either version considered alone.

Frequently asked questions

What is the main difference between Nussbaum and Sen?

The main difference is the degree to which they specify the content of the Capability Approach. Nussbaum proposes ten central capabilities as a minimum threshold of justice, while Sen rejects the need for one canonical list fixed in advance and emphasizes public reasoning and comparative evaluation.

Did Nussbaum and Sen create the Capability Approach together?

No. Sen was the major pioneer of the capability approach, particularly in economics and welfare analysis. Nussbaum later developed her own philosophical version, drawing strongly on Aristotelian ideas, human dignity and political liberalism. They also worked together and co-edited The Quality of Life in 1993.

What are Sen's capabilities?

For Sen, capabilities are the real opportunities people have to achieve valuable functionings. He does not treat them as one fixed universal list but uses the concept to evaluate human freedom, well-being, advantage and agency.

What are Nussbaum's ten capabilities?

Nussbaum identifies ten central capabilities: life; bodily health; bodily integrity; senses, imagination and thought; emotions; practical reason; affiliation; other species; play; and control over one's political and material environment.

Why does Nussbaum want a fixed list?

Nussbaum argues that justice requires substantive standards for identifying unacceptable deprivation. Her list establishes a threshold of central capabilities that she believes every person should be guaranteed as a matter of human dignity.

Why does Sen reject a fixed list?

Sen is skeptical of a single canonical list determined in advance by a philosopher. He argues that the selection and importance of capabilities can depend on the purpose of evaluation and should be informed by public reasoning and democratic discussion.

Does Sen have no list of capabilities?

That is too simplistic. Sen's position is better described as a rejection of one authoritative, universally fixed list. He recognizes that particular evaluations may need to identify particular capabilities, but he does not believe a single canonical list is required for the entire approach.

What is the difference between capabilities and functionings?

A functioning is an achieved state or activity, such as being nourished, being educated or participating in political life. A capability is the genuine opportunity to achieve different functionings. Capabilities therefore capture an important dimension of freedom and choice.

Which thinker focuses more on human dignity?

Nussbaum gives human dignity a particularly explicit role. Her ten central capabilities represent minimum opportunities that she argues are necessary for a life worthy of human dignity. Sen is also concerned with human freedom and well-being but does not build his approach around the same fixed dignity-based list.

Which thinker focuses more on public reasoning?

Sen gives public reasoning a particularly central role in determining how capabilities and injustices should be evaluated. Nussbaum also values democratic deliberation but believes certain fundamental capabilities should be protected even when political majorities might reject them.

How are Sen's ideas connected to human development?

Sen's capability perspective strongly influenced the human development tradition, including the work associated with the UNDP Human Development Reports. It encouraged development analysis to look beyond economic growth toward people's health, education and substantive freedoms.

Is the Human Development Index the same as Sen's Capability Approach?

No. The Human Development Index is a practical composite indicator using a limited set of dimensions. Sen's Capability Approach is a much broader framework for evaluating human advantage, freedom and well-being.

Who is more practical, Nussbaum or Sen?

Both have practical applications, but in different ways. Nussbaum's specified capabilities provide a clearer normative framework for constitutional and policy evaluation, while Sen's comparative and public-reasoning approach is designed to evaluate real alternatives without requiring a complete theory of an ideally just society.

Are Nussbaum and Sen opponents?

Not in the ordinary sense. They share the central capability insight and have collaborated intellectually. Their disagreement concerns how much a capability theory should specify, how justice should be assessed and how much authority should be given to philosophical principles versus public reasoning.

Which approach is better?

There is no simple answer. Nussbaum's approach offers greater normative clarity and a stronger minimum standard, while Sen's approach offers greater openness to democratic reasoning and contextual variation. The choice depends partly on whether one prioritizes a clearly specified account of basic justice or a more open comparative framework.