Martha Nussbaum is an American philosopher at Chicago working across ancient philosophy, ethics, political theory and law, and one of the few contemporary philosophers whose work has changed how institutions measure things.

The capabilities approach

Developed with the economist Amartya Sen, this asks what a person is actually able to do and to be, rather than what resources they hold or how satisfied they report being.

The distinction matters because resources convert into capability at different rates. The same income buys a very different range of lives for someone with a disability, or in a society that bars them from working. A satisfaction measure is worse still, because people adapt their expectations to what they have learned to expect.

Nussbaum specifies a list — life, health, bodily integrity, senses and thought, emotions, practical reason, affiliation, other species, play, control over one's environment — and argues a decent society secures a threshold of each. The approach shaped the UN Human Development Index. See justice and equality.

Emotions as judgments

Upheavals of Thought (2001) argues that emotions are not forces that disturb reasoning but evaluative judgments about what matters. Grief is the recognition that something important has been lost; fear is a judgment about a threat to something you value.

If that is right, emotions can be correct or mistaken, and are part of practical reasoning rather than an obstacle to it — a position with ancestry in Aristotle and against the Stoic treatment of the passions. See apatheia.

Literature and philosophy

She argues that novels do philosophical work that argument cannot, because moral perception requires attention to particulars, and a case described in sufficient detail does something a principle cannot. The position aligns her with Iris Murdoch against the dominant analytic style.