Nussbaum (2011a) has described the general capability approach (not her own specific theory) as consisting of two clusters, one focussing on comparative quality of life and the other on theorising about justice. The two clusters would share a focus on what people are able doing and being, and would share a commitment to five principles: treating each person as an end; a focus on choice and freedom rather than achievements; pluralism about values; being deeply concerned with entrenched social injustices; and ascribing an urgent task to government. However, it has been argued that only two of those (namely, treating each person as an end and pluralism about values) are genuinely essential to each and every capability theory, and that in addition there exists work in the capability approach that does not neatly fit into one of the two clusters that Nussbaum proposes (Robeyns 2016). 