This article considers whether two significant philosophical objections to autonomy-based legal approaches to decision-making for incompetent individuals could be accommodated by the law. These philosophical objections are known as the personal identity and welfare problems. The article first sets out the autonomy-based approaches and their objections. Next, the present legal position is briefly canvassed in a comparative vein. Finally, the article suggests how the personal identity and welfare problems might be accommodated were legislators minded to do so, by proposing specific statutory amendments to the recent English legislation on advance decisions and evaluating their viability, particularly in light of the European Convention on Human Rights.