 The conceptual concerns arise when attempts are made to explain the Asymmetry by reference to principles that assign a special moral status to actual people (or people who will exist if the act under scrutiny is performed; or people who will exist independently of whether that act is performed) that they do not also assign to merely possible people (or to never existing people; or to people whose existence depends on that act being performed) (McMahan 1981; 2009; Persson 2009; Singer 2011, 114; Parfit 2011 vol. 2, 224–225). Similar concerns arise in connection with cases involving cycling, e.g., Parfit’s Tom, Dick and Harry case. See Parfit 2017, 140–146. See also Hare 2007, 503–507 (discussion of double wrongful life; discussion of the Asymmetry).