Singer holds that the right to life is essentially tied to a being's capacity to hold preferences, which in turn is essentially tied to a being's capacity to feel pain and pleasure.

In Practical Ethics, Singer argues in favour of abortion rights on the grounds that fetuses are neither rational nor self-aware, and can therefore hold no preferences.
As a result, he argues that the preference of a mother to have an abortion automatically takes precedence.
In sum, Singer argues that a fetus lacks personhood.

Similar to his argument for abortion rights, Singer argues that newborns lack the essential characteristics of personhood—"rationality, autonomy, and self-consciousness"—and therefore "killing a newborn baby is never equivalent to killing a person, that is, a being who wants to go on living".
Singer has clarified that his "view of when life begins isn't very different from that of opponents of abortion."
He deems it not "unreasonable to hold that an individual human life begins at conception.
If it doesn't, then it begins about 14 days later, when it is no longer possible for the embryo to divide into twins or other multiples."
Singer disagrees with abortion rights opponents in that he does not "think that the fact that an embryo is a living human being is sufficient to show that it is wrong to kill it."
Singer wishes "to see American jurisprudence, and the national abortion debate, take up the question of which capacities a human being needs to have in order for it to be wrong to kill it" as well as "when, in the development of the early human being, these capacities are present."

Singer classifies euthanasia as voluntary, involuntary, or non-voluntary.
Voluntary euthanasia is that to which the subject consents.
He argues in favour of voluntary euthanasia and some forms of non-voluntary euthanasia, including infanticide in certain instances, but opposes involuntary euthanasia.

Religious critics have argued that Singer's ethic ignores and undermines the traditional notion of the sanctity of life.
Singer agrees and believes the notion of the sanctity of life ought to be discarded as outdated, unscientific, and irrelevant to understanding problems in contemporary bioethics.
Bioethicists associated with the disability rights and disability studies communities have argued that his epistemology is based on ableist conceptions of disability.
Singer's positions have also been criticised by some advocates for disability rights and right-to-life supporters, concerned with what they see as his attacks upon human dignity.
Singer has replied that many people judge him based on secondhand summaries and short quotations taken out of context, not his books or articles and, that his aim is to elevate the status of animals, not to lower that of humans.
American publisher Steve Forbes ceased his donations to Princeton University in 1999 because of Singer's appointment to a prestigious professorship.
Nazi-hunter Simon Wiesenthal wrote to organisers of a Swedish book fair to which Singer was invited that "A professor of morals ... who justifies the right to kill handicapped newborns ... is in my opinion unacceptable for representation at your level."
Marc Maurer, president of the National Federation of the Blind, criticised Singer's appointment to the Princeton faculty in a banquet speech at the organisation's national convention in July 2001, claiming that Singer's support for euthanising disabled babies could lead to disabled older children and adults being valued less as well.
Conservative psychiatrist Theodore Dalrymple wrote in 2010 that Singerian moral universalism is "preposterous—psychologically, theoretically, and practically".

In 2002, disability rights activist Harriet McBryde Johnson debated Singer, challenging his belief that it is morally permissible to euthanise new-born children with severe disabilities. "
Unspeakable Conversations", Johnson's account of her encounters with Singer and the pro-euthanasia movement, was published in the New York Times Magazine in 2003.

Singer has experienced the complexities of some of these que
Singer holds that the right to life is essentially tied to a being's capacity to hold preferences, which in turn is essentially tied to a being's capacity to feel pain and pleasure.
In Practical Ethics, Singer argues in favour of abortion rights on the grounds that fetuses are neither rational nor self-aware, and can therefore hold no preferences. As a result, he argues that the preference of a mother to have an abortion automatically takes precedence. In sum, Singer argues that a fetus lacks personhood.
Similar to his argument for abortion rights, Singer argues that newborns lack the essential characteristics of personhood—"rationality, autonomy, and self-consciousness"—and therefore "killing a newborn baby is never equivalent to killing a person, that is, a being who wants to go on living". Singer has clarified that his "view of when life begins isn't very different from that of opponents of abortion." He deems it not "unreasonable to hold that an individual human life begins at conception. If it doesn't, then it begins about 14 days later, when it is no longer possible for the embryo to divide into twins or other multiples." Singer disagrees with abortion rights opponents in that he does not "think that the fact that an embryo is a living human being is sufficient to show that it is wrong to kill it." Singer wishes "to see American jurisprudence, and the national abortion debate, take up the question of which capacities a human being needs to have in order for it to be wrong to kill it" as well as "when, in the development of the early human being, these capacities are present."
Singer classifies euthanasia as voluntary, involuntary, or non-voluntary. Voluntary euthanasia is that to which the subject consents. He argues in favour of voluntary euthanasia and some forms of non-voluntary euthanasia, including infanticide in certain instances, but opposes involuntary euthanasia.
Religious critics have argued that Singer's ethic ignores and undermines the traditional notion of the sanctity of life. Singer agrees and believes the notion of the sanctity of life ought to be discarded as outdated, unscientific, and irrelevant to understanding problems in contemporary bioethics. Bioethicists associated with the disability rights and disability studies communities have argued that his epistemology is based on ableist conceptions of disability. Singer's positions have also been criticised by some advocates for disability rights and right-to-life supporters, concerned with what they see as his attacks upon human dignity. Singer has replied that many people judge him based on secondhand summaries and short quotations taken out of context, not his books or articles and, that his aim is to elevate the status of animals, not to lower that of humans. American publisher Steve Forbes ceased his donations to Princeton University in 1999 because of Singer's appointment to a prestigious professorship. Nazi-hunter Simon Wiesenthal wrote to organisers of a Swedish book fair to which Singer was invited that "A professor of morals ... who justifies the right to kill handicapped newborns ... is in my opinion unacceptable for representation at your level." Marc Maurer, president of the National Federation of the Blind, criticised Singer's appointment to the Princeton faculty in a banquet speech at the organisation's national convention in July 2001, claiming that Singer's support for euthanising disabled babies could lead to disabled older children and adults being valued less as well. Conservative psychiatrist Theodore Dalrymple wrote in 2010 that Singerian moral universalism is "preposterous—psychologically, theoretically, and practically".
In 2002, disability rights activist Harriet McBryde Johnson debated Singer, challenging his belief that it is morally permissible to euthanise new-born children with severe disabilities. "Unspeakable Conversations", Johnson's account of her encounters with Singer and the pro-euthanasia movement, was published in the New York Times Magazine in 2003.
Singer has experienced the complexities of some of these que
Peter Singer