Fletcher (1972), a philosopher and ethicist, proposed positive and negative criteria for personhood, but he did not suggest that one must fulfill all these criteria to be a person. Positive criteria’s are minimal intelligence, self awareness, self control, a sense of time, sense of futurity, sense of past memory, capability to relate to others, concern for others, communication, curiosity, change and changeability, idiosyncrasy and neocortical function. Negative criteria are antitechnology, essentially sexual, a bundle of rights and compelled to worship.
Singer (1972) believed that it should be morally permissible to kill disabled newborns that lack capability of becoming sentient. If communication ability remains a criteria for personhood then apes should have moral state of person and new born should not due to lack of capability to communicate. Tooley (1983) believed that use of language is critical to personhood and support aborting infant and killing newborn who has or is at risk of having disability. Englehardt (1975) exclude newborn as person based on self concept as critical criteria to personhood and newborn lacks self concept. Richard McCormick (1974), a priest and catholic theologian, also support withholding life sustaining treatment from infant who are ‘abnormal’ and unlikely to develop human relations.
If newborn lacks the cognitive ability to think, reason and plan and will likely never to develop them then philosophers suggest it permissible to take life. These arguments