The concept of mental capacity sits at the junction of two of the most powerful discourses in our society today: autonomy, and paternalism. The Mental Capacity Act 2005 (MCA) is concerned with autonomy in two interlinked senses:
- Autonomy meant as the right to determine one's own course, free from external interference (closely linked to the concept of negative liberty and Liberalism in political philosophy);
- Autonomy meant as the capacity for self-governance of one's actions (often called 'personal autonomy' in Philosophy).
At base, the MCA serves a gatekeeping function between actions (or inaction) predicated upon discourses of autonomy or paternalism. (Very) roughly put: if you have the capacity for autonomous (self-governing) decision making, you should enjoy the right to autonomous (free from interference) decision making. If you don't have the capacity for autonomous decision making, then paternalistic interferences with your affairs are permitted. In theory, under the MCA a person should not be denied the right to make decisions they are capable of making; but equally they should not suffer the consequences of decisions they are incapable of making.