Second, as indicated above, in developing a capability theory of justice we must decide whether we want it to be an outcome or an opportunity theory, that is, whether we think that we should assess injustices in terms of functionings, or rather in terms of capabilities, or a mixture. At the level of theory and principles, most theorists of justice endorse the view that justice is done if all have equal genuine opportunities, or if all reach a minimal threshold of capability levels. Translated to the capability language, this would imply that at the level of theory and principles, capabilities are the relevant metric of justice, and not functionings. However, not everyone subscribes to this view. Phillips (2004) has been a prominent voice arguing for equality of outcome, rather than opportunities. In the capability literature, Fleurbaey (2002) has argued against the view to take only capabilities into account and has defended a focus on ‘refined functionings’ (being the combination of functionings and capabilities).