This article considers the legal treatment of those suffering from dementia. In particular it considers those who are on the borderlines of mental capacity. It rejects the current law which regards the principle of autonomy as always protecting the rights of those with marginal capacity to make decisions for themselves, and the exclusive weight attached to the best interests approach in the case of those found lacking capacity. Rather it argues for a more nuanced approach under which the views of those lacking capacity are given weight and respect, while the wishes of those of marginal capacity can be overridden in some circumstances.