Chapter 4 explains how in traditional liberalism, autonomy as the ability to reason has been recognised as the foundation for personhood, thereby excluding adults with cognitive disability. Interpretations of Article 12 that require the abolition of decision-making by substitutes refashion autonomy from being marked by rationality and independence to being marked by shared personhood and interdependence so as to include adults with cognitive disability. I argue that these refashionings ultimately fail because despite avowals to the contrary, they perpetuate the privileging of rationality and of the bounded, independent individual. They also fail to recognise the interdependency of Article 12 with other rights in the CRPD, especially socio-economic rights. I argue that a concept of autonomy as achievement, as the development of autonomy competencies, as demanding the availability of a range of options and as demanding recognition of the indivisibility of human rights is the autonomy underpinning Article 12 and the CRPD.