"A person is a being, such as a human, that has certain capacities or attributes constituting personhood, which in turn is defined differently by different authors in different disciplines, and less formally by different cultures in different times and places.
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"Personhood is the status of being a person. Defining personhood is a controversial topic in philosophy and law, and is closely tied to legal and political concepts of citizenship, equality, and liberty. According to law, only a natural person or legal personality has rights, protections, privileges, responsibilities, and legal liability. Personhood continues to be a topic of international debate, and has been questioned during the abolition of slavery and the fight for women's rights, in debates about abortion, fetal rights and reproductive rights, and in animal rights advocacy.
"Various debates have focused on questions about the personhood of different classes of entities. Historically, the personhood of animals, women, and slaves has been a catalyst of social upheaval. In most societies today, living adult humans are usually considered persons, but depending on the context, theory or definition, the category of 'person' may be taken to include such non-human entities as animals, artificial intelligences, or extraterrestrial life, as well as legal entities such as corporations, sovereign states and other polities, or estates in probate. The category may exclude some human entities in prenatal development, and those with extreme mental impairment."
Because this definition has built-in limits that impede our purposes – which is to say, for the purpose of eliminating the far too limited definition of person that includes only members of our species, homo sapiens sapiens (HSS) - it is necessary to evolve that definition, adapt it into a more inclusive form. A "natural person," legally speaking, means a human being. Other entities, such as corporations, ships at sea, and states, also have legal personhood – a bone of some contention here in the U.S. For our purposes, legal recognition of corporations and states and ships serves little purpose. For that reason, I hope to focus on the a notion of personhood that includes natural persons, but also extends to include not only nonhuman biological species who meet certain criteria, but also abandons substrate chauvinism by embracing the possibility of technological beings meeting those same criteria, and therefore qualifying as persons.
I would like to begin with some defining characteristics.
Intelligence
Intelligence is a term that can refer to a broad range of abilities, including those of stock-trading software that decides when to execute a transaction – too diffuse a term to be very useful for our purposes. General Intelligence, however, may be a flexible enough concept. In the field of artificial intelligence, Artificial General Intelligence (AGI), generally speaking, has been the quest to create computer systems or entities with human-like intelligence.
"General intelligence, also known as g factor, refers to the existence of a general intelligence that influences performance on mental ability measures. The existence of general intelligence was first described by Charles Spearman in 1904. According to Spearman, this g factor was responsible for overall performance on mental ability tests."
Sentience
Sentience is a quality that's also useful in attempting to define personhood.
"Sentience is the ability to feel, perceive, or be conscious, or to have subjective experiences. Eighteenth century philosophers used the concept to distinguish the ability to think ('reason') from the ability to feel ('sentience'). In modern western philosophy, sentience is the ability to have sensations or experiences (described by some thinkers as 'qualia'). For Eastern philosophy, sentience is a metaphysical quality of all things that requires respect and care. The concept is central to the philosophy of animal rights, because sentience is necessary for the ability to suffer, which entails certain rights. In science fiction, non-human characters described as 'sentient' typically have similar abilities, qualities and rights as human beings.
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"In the philosophy of consciousness, 'sentience' can refer to the ability of any entity to have subjective perceptual experiences, or 'qualia'. This is distinct from other aspects of the mind and consciousness, such as creativity, intelligence, sapience, self-awareness, and intentionality (the ability to have thoughts that mean something or are "about" something). Sentience is a minimalistic way of defining 'consciousness', which is otherwise commonly used to collectively describe sentience plus other characteristics of the mind."
No hurt
For sentience, many interested in the philosophy of rights for nonhuman animals emphasize a being's ability to experience pain and pleasure; if a being can experience pain, says this argument, then it is wrong to inflict pain upon that being. Thus, a being who can experience suffering should not arbitrarily be subjected to suffering, whether physical or psychological.
This only seems reasonable.
Consciousness
A quick trip to Dictionary.com yields the following:
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con·scious·ness [kon-shuhs-nis] noun
1. The state of being conscious; awareness of one's own existence, sensations, thoughts, surroundings, etc. 2. the thoughts and feelings, collectively, of an individual or ofan aggregate of people: the moral
consciousness of a nation.
3. full activity of the mind and senses, as in waking life: toregain consciousness after fainting.
4. awareness of something for what it is; internal knowledge:consciousness of wrongdoing.
5. concern, interest, or acute awareness: class consciousness.
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This may be as close as we get, as the term itself is much-contested. Consciousness, or the ability to attain consciousness – as opposed to an inability to attain consciousness – would seem to be an integral part of personhood. When a human being cannot become conscious and meets a few other criteria such as, say, brain death, we refer to this as a persistent vegetative state. Though a living biological body may remain, brain death means the end of that person's conscious existence, hence the more crude tendency to refer to a human being who's in such a state as a vegetable. A human being who has suffered brain death, yet whose body remains alive, is still a human being but, for the purposes of our definition, is no longer a person, for what made Zir a person has ceased to be.
How Do We Know?
Or: How could we prove that these qualities exist in any being?
Tough question. Not being a solipsist, I assume when I meet other human beings that they are, in fact, not elaborate simulations placed before me to trick me. As Bishop Berkeley (and countless others have) observed, I can really only go on what I observe about phenomena in the world around me; I have only these fallible senses to rely upon. This holds true for all of us, ultimately, whether we use technology to learn of things we could not otherwise directly sense or not. So we must go on what we can observe about nonhuman beings.
A Turing Test would challenge a nonhuman being to fool humans into believing that ze, too, was human. (Recently, some robots involved in a Turing test were more successful at appearing to be human than were human participants.) That's useful if we wish to create such a being, and if that is what we mean to test its ability to do. No, what we need to test for are such indicators of a sense of self as recognition of one's reflection – the Mirror Test.
"The mirror test is a measure of self-awareness developed by Gordon Gallup Jr in 1970.
The test gauges self-awareness by determining whether an animal can recognize its own reflection in a mirror as an image of itself.
This is accomplished by surreptitiously marking the animal with an odourless dye, and observing whether the animal reacts in a manner consistent with it being aware that the dye is located on its own body.
Such behaviour might include turning and adjusting of the body in order to better view the marking in the mirror, or poking at the marking on its own body with a finger while viewing the mirror."
This is a capacity shared by the other Great Apes (by which I mean, the nonhuman Great Apes, as we are Great Apes, as well); cetaceans – that is whales, dolphins, and porpoises; and elephants – all species whose nonhuman personhood status the (IEET) Institute for Ethics and Emerging Technologies' Rights of Nonhuman Persons Program advocates. Interestingly, human children do not generally pass this test until 1-1/2 to 2 years of age (a factor which obviously does not call into question their personhood).
A being with consciousness, sentience, and general intelligence may even be a being who can make some claim to personhood. An advanced enough technological being who can demonstrate AGI as well as artificial sentience and apparent consciousness will most likely be able to make such a claim and demand zir recognition and rights as a nonhuman person, though such a person would not technically be alive, in the biological sense.
Interestingly, in August of this year, an international group of prominent scientists came together to pen and sign The Cambridge Declaration of Consciousness (PDF).
George Dvorsky, writing for io9 and the IEET, noted that "cognitive scientists, neuropharmacologists, neurophysiologists, neuroanatomists, and computational neuroscientists — all of whom were attending the Francis Crick Memorial Conference on Consciousness in Human and Non-Human Animals." Dvorsky is also the program director for the IEET's Rights of Nonhuman Persons Program and an agenda-driven futurist/activist.
The Cambridge Declaration further states, "The field of Consciousness research is rapidly evolving. Abundant new techniques and strategies for human and non-human animal research have been developed. Consequently, more data is becoming readily available, and this calls for a periodic reevaluation of previously held preconceptions in this field. Studies of non-human animals have shown that homologous brain circuits correlated with conscious experience and perception can be selectively facilitated and disrupted to assess whether they are in fact necessary for those experiences. Moreover, in humans, new non-invasive techniques are readily available to survey the correlates of consciousness. "The neural substrates of emotions do not appear to be confined to cortical structures. In fact, subcortical neural networks aroused during affective states in humans are also critically important for generating emotional behaviors in animals.
Artificial arousal of the same brain regions generates corresponding behavior and feeling states in both humans and non-human animals. Wherever in the brain one evokes instinctual emotional behaviors in non-human animals, many of the ensuing behaviors are consistent with experienced feeling states, including those internal states that are rewarding and punishing. Deep brain stimulation of these systems in humans can also generate similar affective states. Systems associated with affect are concentrated in subcortical regions where neural homologies abound. Young human and nonhuman animals without neocortices retain these brain-mind functions. Furthermore, neural circuits supporting behavioral/electrophysiological states of attentiveness, sleep and decision making appear to have arisen in evolution as early as the invertebrate radiation, being evident in insects and cephalopod mollusks (e.g., octopus)."
No Hurt, No Foul
I'd like to make an important point here: Recognizing the rights of another being does not take away from your rights as a human being, any more than recognition of, say, gender considerations beyond our usual gender-binary dynamic takes away from the rights of male and female human beings.
Recognizing the civil rights of others, such as the right of same-sex couples to marry, in no way lessens the right of opposite-sex couples' right to marry.
And in the same way, recognition of the philosophical status of personhood in nonhuman persons in no way infringes upon the rights or personhood status of those who already enjoy them.