 In addition, decision-making capacity is becoming more and more relevant as certain types of ethical questions become hot topics of public debate. For example, decisional-capacity is obviously of great importance in relation to medical-assistance-in-dying laws  (MAID),[4]  and yet the public often fails to understand what is actually meant by decisional-capacity as well as how variable the practices of assessing capacity really are (Kim, Appelbaum, et al. 2011; Seyfried, Ryan, &amp; Kim 2013). This is particularly important since one of the most divisive issues currently concerns whether those with mental illness or cognitive impairment should be candidates for assisted dying (Stewart, Peisah, &amp; Draper 2011; Broome &amp; de Cates 2015; Price 2015; Schuklenk &amp; van de Vathorst 2015; Appelbaum 2016; Charland, Lemmens, &amp; Wada 2016; Doernberg, Peteet, &amp; Kim 2016; Kim &amp; Lemmens 2016; Blikshavn, Husum, &amp; Magelssen 2017). As this entry makes clear, some of the most difficult questions about decisional capacity arise specifically in the case of mental illness, making it even harder to determine whether MAID for the mentally ill is a policy that could be implemented appropriately, where “appropriate” here just means an implementation that strikes just the right balance between protecting the truly vulnerable, on the one hand, and promoting freedom for those who can meaningfully exercise it, on the other.