If we are to believe the Commentary on the United Nations Convention on the Rights of People with Disabilities (2014), article 12 (equality before the law) aims to replace decision-making capacity assessment with a focus on ‘rights, will and preferences’. Despite this, and New Zealand having ratified the Convention, the draft NZ Mental Health Act introduces a decision-making capacity test into the existing criteria for being subject to the powers of the act.
The UNCRPD raises a fundamental question: do we really need to assess decision-making capacity at all? Why not replace capacity tests with a ‘rights, will and preferences’ approach? It might have helped us to answer this question if the convention, the commentary on it, or the NZ draft MHA defined ‘will and preferences’. My aim in this paper is to see if I can construct an account of will and preferences such that it reflects the underlying logic of the Convention (i.e. is not just another way of talking about decision-making capacity) and can then be inspected for plausibility.