[The capability theory avoids such pitfalls because it insists that quality of life must take into account such incommensurable factors as access to education, quality of personal relationships, political freedom, etc.] The right question to ask seemed to us to be: what are people actually able to do and to be? ... And we look at capabilities rather than actual functioning because we think it's the opportunities that are important. People should be free to choose which ones to use.

Martha Nussbaum