Some critics reject the "natural capacities" view on the basis that it takes mere species membership or genetic potential as a basis for respect (in essence a charge of speciesism), or because it entails that anencephalic infants and the irreversibly comatose have a full right to life. Moreover, as with Marquis's argument (see below), some theories of personal identity would support the view that the embryo will never "itself" develop complex mental qualities (rather, it will simply give rise to a distinct substance or entity that "will" have these qualities), in which case the "natural capacities" argument would fail. Respondents to this criticism argue that the noted human cases in fact would not be classified as persons as they do not have a natural capacity to develop any psychological features.