Personism is an ethical philosophy of personhood as typified by the thought of the preference utilitarian philosopher Peter Singer. It amounts to a branch of secular humanism with an emphasis on certain rights-criteria. Personists believe that rights are conferred to the extent that a creature is a person. Michael Tooley provides the relevant definition of a person, saying it is a creature that "capable of desiring to continue as a subject of experience and other mental states". A worldview like secular humanism is personism when the empathy and values are extended to the extent that the creature is a person (apes get very similar rights, insects get vastly fewer rights, etc.).
Consequently, a member of the human species may not necessarily fit the definition of “person” and thereby not receive all the rights bestowed to a person. This philosophy is also supposedly open to the idea that such non-human persons as machines, animals (especially the parahuman ones), and extraterrestrial intelligences may be entitled to certain rights currently granted only to humans. Personism may have views in common with transhumanism.
Singer argues that "...despite many individual exceptions, humanists have on the whole been unable to free themselves from one of the most central of these Christian dogmas: the prejudice of Speciesism."
Singer's philosophy has natural conclusions that contradict his own account as well as conflict with common philosophical intuition. A case in point: Singer argues that fetuses and even newborn humans are not yet persons and do not, therefore, have the same rights as an adult human or any other person: most famously, he deprives them of the right to life, as, starting from a preference utilitarian view of ethics with Singer's concept of personhood, it follows that a non-person can not have preferences, thus any preference of a person takes moral precedent, whether it involves death of the non-person or not (see Singer on abortion, euthanasia, and infanticide). On the other hand, Michael Tooley distinguished between creatures that only have the possibility of becoming a person as he defined it (e.g. fetuses, or spermatozoa and an ovum) and a creature that already has that capacity, and is already owed moral consideration accordingly (e.g. a sleeping person).
Personism also suggests that animals deserve more rights than they are currently granted, since their goals and desires have some moral weight. This includes a right to life, since death is the greatest obstruction to a person's goals. Depending on their level of sentience, an animal should be given more rights (e.g. a cow is more of a "person" than a fly). Singer himself is a vegan, and advocates for vegetarianism. He adds that he is concerned with the rights of any creatures that currently exist, not with "potential" persons (thus he focuses on the treatment of today's living livestock rather than possible future generations).
- Rethinking Peter Singer: a Christian Critique, by Gordon R. Preece
- Applied ethics: a non-consequentialist approach, by David S. Oderberg
- Humanism and Personism: The false philosophy of Peter Singer, by Jenny Teichman
- Singer, Peter (Oct/Nov 2004). "Taking Humanism Beyond Speciesism". Free Inquiry 24 (6): 19–21. Retrieved 16 February 2012.
- Bioethics: An Anthology, by Helga Kuhse, Peter Singer
- Jacqueline A. Laing (1997), “Innocence and Consequentialism: Inconsistency, Equivocation and Contradiction in the Philosophy of Peter Singer” in Human Lives: Critical Essays on Consequentialist Bioethics, eds. J. A. Laing with D. S. Oderberg. London, Macmillan, pp. 196-224
 Other uses
- Personism can refer to the actual philosophical topic of what constitutes a person
- Personism can refer to a form of poetry mentioned by Frank O'Hara in which the poem is written directly towards another person.