Sentience is the capacity to experience

feeling Feelings are subjective self-contained phenomenal experiences. According to the ''APA Dictionary of Psychology'', a feeling is "a self-contained phenomenal experience"; and feelings are "subjective, evaluative, and independent of the sensations ...

s and sensations. The word was first coined by philosophers in the 1630s for the concept of an ability to feel, derived from Latin '' sentientem'' (a feeling), to distinguish it from the ability to think (''

reason Reason is the capacity of consciously applying logic by drawing conclusions from new or existing information, with the aim of seeking the truth. It is closely associated with such characteristically human activities as philosophy, science, ...

''). In modern Western philosophy, sentience is the ability to experience sensations. In different Asian religions, the word 'sentience' has been used to translate a variety of concepts. In

science fiction Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel unive ...

, the word "sentience" is sometimes used interchangeably with "

sapience Wisdom, sapience, or sagacity is the ability to contemplate and act using knowledge, experience, understanding, common sense and insight. Wisdom is associated with attributes such as unbiased judgment, compassion, experiential self-knowledge, ...

", "

self-awareness In philosophy of self, self-awareness is the experience of one's own personality or individuality. It is not to be confused with consciousness in the sense of qualia. While consciousness is being aware of one's environment and body and lifesty ...

", or "

consciousness Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...

". Some writers differentiate between the mere ability to perceive sensations, such as light or pain, and the ability to perceive

emotion Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...

s, such as

fear Fear is an intensely unpleasant emotion in response to perceiving or recognizing a danger or threat. Fear causes physiological changes that may produce behavioral reactions such as mounting an aggressive response or fleeing the threat. Fear ...

grief Grief is the response to loss, particularly to the loss of someone or some living thing that has died, to which a bond or affection was formed. Although conventionally focused on the emotional response to loss, grief also has physical, cogni ...

. The subjective awareness of experiences by a

conscious Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...

individual are known as

qualia In philosophy of mind, qualia ( or ; singular form: quale) are defined as individual instances of subjective, conscious experience. The term ''qualia'' derives from the Latin neuter plural form (''qualia'') of the Latin adjective '' quālis'' () ...

in Western

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...

Philosophy and sentience

In philosophy, different authors draw different distinctions between ''

'' and sentience. According to

Antonio Damasio Antonio Damasio ( pt, António Damásio) is a Portuguese-American neuroscientist. He is currently the David Dornsife Chair in Neuroscience, as well as Professor of Psychology, Philosophy, and Neurology, at the University of Southern California, ...

, sentience is a minimalistic way of defining consciousness, which otherwise commonly and collectively describes sentience plus further features of the

mind The mind is the set of faculties responsible for all mental phenomena. Often the term is also identified with the phenomena themselves. These faculties include thought, imagination, memory, will, and sensation. They are responsible for various m ...

and consciousness, such as

creativity Creativity is a phenomenon whereby something new and valuable is formed. The created item may be intangible (such as an idea, a scientific theory, a musical composition, or a joke) or a physical object (such as an invention, a printed literary w ...

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can b ...

, and

intentionality ''Intentionality'' is the power of minds to be about something: to represent or to stand for things, properties and states of affairs. Intentionality is primarily ascribed to mental states, like perceptions, beliefs or desires, which is why it ha ...

(the ability to have thoughts about something). These further features of consciousness may not be necessary for sentience, which is the capacity to feel sensations and emotions.

Consciousness

According to

Thomas Nagel Thomas Nagel (; born July 4, 1937) is an American philosopher. He is the University Professor of Philosophy and Law Emeritus at New York University, where he taught from 1980 to 2016. His main areas of philosophical interest are legal philosophy, ...

in his paper " What Is It Like to Be a Bat?", ''consciousness'' can refer to the ability of any entity to have subjective perceptual experiences, or as some philosophers refer to them, "

"—in other words, the ability to have states that it ''feels like something'' to be in. Some philosophers, notably

Colin McGinn Colin McGinn (born 10 March 1950) is a British philosopher. He has held teaching posts and professorships at University College London, the University of Oxford, Rutgers University, and the University of Miami. McGinn is best known for his wor ...

, believe that the physical process causing consciousness to happen will never be understood, a position known as "

new mysterianism New mysterianism, or commonly just mysterianism, is a philosophical position proposing that the hard problem of consciousness cannot be resolved by humans. The unresolvable problem is how to explain the existence of qualia (individual instances o ...

." They do not deny that most other aspects of consciousness are subject to scientific investigation but they argue that

will never be explained. Other philosophers, such as

Daniel Dennett Daniel Clement Dennett III (born March 28, 1942) is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relat ...

, argue that qualia are not a meaningful concept. Regarding

animal consciousness Animal consciousness, or animal awareness, is the quality or state of self-awareness within a non-human animal, or of being aware of an external object or something within itself. In humans, consciousness has been defined as: sentience, aware ...

, according to the Cambridge Declaration of Consciousness, which was publicly proclaimed on 7 July 2012 at Cambridge University, consciousness is that which requires specialized neural structures, chiefly neuroanatomical, neurochemical, and neurophysiological substrates, which manifests in more complex organisms as the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

, to exhibit consciousness. Accordingly, only organisms that possess these substrates, all within the animal kingdom, are said to be conscious.

Sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

placozoa The Placozoa are a basal form of marine free-living (non-parasitic) multicellular organism. They are the simplest in structure of all animals. Three genera have been found: the classical ''Trichoplax adhaerens'', ''Hoilungia hongkongensis'', an ...

ns, and

mesozoa The Mesozoa are minuscule, worm-like parasites of marine invertebrates. Generally, these tiny, elusive creatures consist of a somatoderm (outer layer) of ciliated cells surrounding one or more reproductive cells. A recent study recovered Mesoz ...

ns, with simple body plans and no nervous system, are the only members of the animal kingdom that possess no consciousness.

Phenomenal vs. affective consciousness

David Chalmers David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Universi ...

argues that sentience is sometimes used as shorthand for ''phenomenal consciousness'', the capacity to have any subjective experience at all, but sometimes refers to the narrower concept of ''affective consciousness'', the capacity to experience subjective states that have affective valence (i.e., a positive or negative character), such as pain and pleasure.

Recognition paradox and relation to sapience

While it has been traditionally assumed that sentience and sapience are, in principle, independent of each other, there are criticisms of that assumption. One such criticism is about recognition paradoxes, one example of which is that an entity that cannot distinguish a spider from a non-spider cannot be arachnophobic. More generally, it is argued that since it is not possible to attach an emotional response to stimuli that cannot be recognized, emotions cannot exist independently of cognition that can recognize. The claim that precise recognition exists as specific attention to some details in a modular mind is criticized both with regard to data loss as a small system of disambiguating synapses in a module physically cannot make as precise distinctions as a bigger synaptic system encompassing the whole brain, and for energy loss as having one system for motivation that needs some built-in cognition to recognize anything anyway and another cognitive system for making strategies would cost more energy than integrating it all in one system that use the same synapses. Data losses inherent in all information transfer from more precise systems to less precise systems are also argued to make it impossible for any imprecise system to use a more precise system as an "emissary", as a less precise system would not be able to tell whether the outdata from the more precise system was in the interest of the less precise system or not.

Empirical data on conditioned reflex precision

The original studies by

Ivan Pavlov Ivan Petrovich Pavlov ( rus, Ива́н Петро́вич Па́влов, , p=ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf, a=Ru-Ivan_Petrovich_Pavlov.ogg; 27 February 1936), was a Russian and Soviet experimental neurologist, psychologist and physiol ...

that showed that

conditioned reflex Classical conditioning (also known as Pavlovian or respondent conditioning) is a behavioral procedure in which a biologically potent stimulus A stimulus is something that causes a physiological response. It may refer to: *Stimulation **Stimulus ...

es in human children are more discriminating than those in dogs, human children salivating only at ticking frequencies very close to those at which food was served while dogs drool at a wider range of frequencies, have been followed up in recent years with comparative studies on more species. It is shown that both brain size and brain-wide connectivity contribute to make perception more discriminating, as predicted by the theory of a brain-wide perception system but not by the theory of separate systems for emotion and cognition.

Eastern religions

Eastern religions including

Hinduism Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...

Buddhism Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religion or philosophical tradition based on teachings attributed to the Buddha. It originated in northern India as a -movement in the 5th century BCE, and gra ...

Sikhism Sikhism (), also known as Sikhi ( pa, ਸਿੱਖੀ ', , from pa, ਸਿੱਖ, lit=disciple', 'seeker', or 'learner, translit=Sikh, label=none),''Sikhism'' (commonly known as ''Sikhī'') originated from the word ''Sikh'', which comes fro ...

, and

Jainism Jainism ( ), also known as Jain Dharma, is an Indian religions, Indian religion. Jainism traces its spiritual ideas and history through the succession of twenty-four tirthankaras (supreme preachers of ''Dharma''), with the first in the current ...

recognise

non-human Non-human (also spelled nonhuman) is any entity displaying some, but not enough, human characteristics to be considered a human. The term has been used in a variety of contexts and may refer to objects that have been developed with human intelligen ...

s as sentient beings. The term ''sentient beings'' is translated from various Sanskrit terms (''jantu, bahu jana, jagat, sattva'') and "conventionally refers to the mass of living things subject to illusion, suffering, and rebirth (Saṃsāra)".Getz, Daniel A. (2004). "Sentient beings"; cited in Buswell, Robert E. (2004). ''Encyclopedia of Buddhism''. Volume 2. New York, USA: Macmillan Reference USA. (Volume 2): pp.760 In some forms of Buddhism plants, stones and other inanimate objects are considered to be 'sentient'. In Jainism many things are endowed with a soul, '' jīva'', which is sometimes translated as 'sentience'. Some things are without a soul, ''

ajīva ''Ajiva'' (Sanskrit) is anything that has no soul or life, the polar opposite of " jīva" (soul). Because ''ajiva'' has no life, it does not accumulate ''karma'' and cannot die. Examples of ajiva include chairs, computers, paper, plastic, etc. ...

'', such as a chair or spoon. There are different rankings of ''jīva'' based on the number of senses it has. Water, for example, is a sentient being of the first order, as it is considered to possess only one sense, that of touch. In Jainism and Hinduism, this is related to the concept of

ahimsa Ahimsa (, IAST: ''ahiṃsā'', ) is the ancient Indian principle of nonviolence which applies to all living beings. It is a key virtue in most Indian religions: Jainism, Buddhism, and Hinduism.Bajpai, Shiva (2011). The History of India � ...

, non-violence toward other beings. Sentience in Buddhism is the state of having senses. In Buddhism, there are six senses, the sixth being the subjective experience of the mind. Sentience is simply awareness prior to the arising of

Skandha (Sanskrit) or (Pāḷi) means "heaps, aggregates, collections, groupings". In Buddhism, it refers to the five aggregates of clinging (), the five material and mental factors that take part in the rise of craving and clinging. They are also ...

. Thus, an animal qualifies as a sentient being. According to Buddhism, sentient beings made of pure consciousness are possible. In

Mahayana ''Mahāyāna'' (; "Great Vehicle") is a term for a broad group of Buddhist traditions, texts, philosophies, and practices. Mahāyāna Buddhism developed in India (c. 1st century BCE onwards) and is considered one of the three main existing bra ...

Buddhism, which includes

Zen Zen ( zh, t=禪, p=Chán; ja, text= 禅, translit=zen; ko, text=선, translit=Seon; vi, text=Thiền) is a school of Mahayana Buddhism that originated in China during the Tang dynasty, known as the Chan School (''Chánzong'' 禪宗), and ...

and

Tibetan Buddhism Tibetan Buddhism (also referred to as Indo-Tibetan Buddhism, Lamaism, Lamaistic Buddhism, Himalayan Buddhism, and Northern Buddhism) is the form of Buddhism practiced in Tibet and Bhutan, where it is the dominant religion. It is also in majo ...

, the concept is related to the

Bodhisattva In Buddhism, a bodhisattva ( ; sa, 𑀩𑁄𑀥𑀺𑀲𑀢𑁆𑀢𑁆𑀯 (Brahmī), translit=bodhisattva, label=Sanskrit) or bodhisatva is a person who is on the path towards bodhi ('awakening') or Buddhahood. In the Early Buddhist schools ...

, an enlightened being devoted to the liberation of others. The first

vow A vow ( Lat. ''votum'', vow, promise; see vote) is a promise or oath. A vow is used as a promise, a promise solemn rather than casual. Marriage vows Marriage vows are binding promises each partner in a couple makes to the other during a wedd ...

of a Bodhisattva states, "Sentient beings are numberless; I vow to free them."

Animal welfare, rights, and sentience

Sentience has been a central concept in the animal rights movement, tracing back to the well-known writing of

Jeremy Bentham Jeremy Bentham (; 15 February 1748 Old_Style_and_New_Style_dates">O.S._4_February_1747.html" ;"title="Old_Style_and_New_Style_dates.html" ;"title="nowiki/>Old Style and New Style dates">O.S. 4 February 1747">Old_Style_and_New_Style_dates.htm ...

in ''

An Introduction to the Principles of Morals and Legislation ''An Introduction to the Principles of Morals and Legislation'' is a book by the English philosopher and legal theorist Jeremy Bentham "originally printed in 1780, and first published in 1789." Bentham's "most important theoretical work," it is w ...

'': "The question is not, Can they reason? nor, Can they talk? but, Can they suffer?"

Richard D. Ryder Richard Hood Jack Dudley Ryder (born 3 July 1940) is an English writer, psychologist, and animal rights advocate. Ryder became known in the 1970s as a member of the Oxford Group (animal rights), Oxford Group, a group of intellectuals loosely c ...

defines

sentientism Sentiocentrism, sentio-centrism, or sentientism is an ethical view that places sentient individuals (i.e., basically conscious beings) at the center of moral concern. Both humans and other sentient individuals have rights and/or interests that m ...

broadly as the position according to which an entity has moral status if and only if it is sentient. In David Chalmer's more specific terminology, Bentham is a ''narrow sentientist'', since his criterion for moral status is not only the ability to experience any phenomenal consciousness at all, but specifically the ability to experience conscious states with negative affective valence (i.e. suffering). Animal welfare and rights advocates often invoke similar capacities. For example, the documentary ''

Earthlings Earthling or Earthlings may refer to: Film and television * ''Earthling'' (film), a 2010 sci-fi film * ''Earthlings'' (film), a 2005 animal rights documentary * ''The Earthling'', a 1980 drama film * "Earthling" (''Fringe''), a 2009 TV episode ...

'' argues that while animals do not have all the desires and ability to comprehend as do humans, they do share the desires for food and water, shelter and companionship, freedom of movement and avoidance of pain.Monson S (2005), "Earthlings". Animal-welfare advocates typically argue that any sentient being is entitled, at a minimum, to protection from unnecessary suffering, though animal-rights advocates may differ on what rights (e.g., the right to life) may be entailed by simple sentience.

Sentiocentrism Sentiocentrism, sentio-centrism, or sentientism is an ethical view that places sentient individuals (i.e., basically conscious beings) at the center of moral concern. Both humans and other sentient individuals have rights and/or interests that m ...

describes the theory that sentient individuals are the center of moral concern.

Gary Francione Gary Lawrence Francione (born May 1954) is an American academic in the fields of law and philosophy. He is Board of Governors Professor of Law and Katzenbach Scholar of Law and Philosophy at Rutgers University in New Jersey. He is also a visitin ...

also bases his

abolitionist Abolitionism, or the abolitionist movement, is the movement to end slavery. In Western Europe and the Americas, abolitionism was a historic movement that sought to end the Atlantic slave trade and liberate the enslaved people. The British ...

theory of animal rights, which differs significantly from Singer's, on sentience. He asserts that, "All sentient beings, humans or nonhuman, have one right: the basic right not to be treated as the property of others."

Andrew Linzey Andrew Linzey (born 2 February 1952) is an English Anglican priest, theologian, and prominent figure in Christian vegetarianism. He is a member of the Faculty of Theology at the University of Oxford, and held the world's first academic post in Et ...

, founder of the

Oxford Centre for Animal Ethics The Ferrater Mora Oxford Centre for Animal Ethics is an organisation based in Oxford which promotes animal ethics. History The centre was founded in Oxford in 2006 by Andrew Linzey, a member of the Faculty of Theology at the University of Oxf ...

in England, considers recognising animals as sentient beings as an aspect of his Christianity. The Interfaith Association of Animal Chaplains encourages animal ministry groups to adopt a policy of recognising and valuing sentient beings. In 1997 the concept of animal sentience was written into the basic law of the European Union. The legally binding protocol annexed to the Treaty of Amsterdam recognises that animals are "sentient beings", and requires the EU and its member states to "pay full regard to the welfare requirements of animals".

Alleged sentience of artificial intelligence

It is a subject of debate as to whether artificial intelligence can potentially display, or has displayed, the level of awareness and cognitive ability required of sentience in animals. Notably, the discussion on the topic of alleged sentience of artificial intelligence has been reignited as a result of recent (as of mid-2022) claims made about

Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...

's LaMDA

artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech re ...

system that it is "sentient" and had a "

soul In many religious and philosophical traditions, there is a belief that a soul is "the immaterial aspect or essence of a human being". Etymology The Modern English noun ''soul'' is derived from Old English ''sāwol, sāwel''. The earliest attes ...

LaMDA LaMDA, which stands for Language Model for Dialogue Applications, is a family of conversational neural language models developed by Google. The first generation was announced during the 2021 Google I/O keynote, while the second generation was a ...

(

Language Model A language model is a probability distribution over sequences of words. Given any sequence of words of length , a language model assigns a probability P(w_1,\ldots,w_m) to the whole sequence. Language models generate probabilities by training on ...

for Dialogue Applications) is an

artificial intelligence system Artificial Intelligence System (AIS) was a volunteer computing project undertaken by Intelligence Realm, Inc. with the long-term goal of simulating the human brain in real time, complete with artificial consciousness and artificial general intell ...

that creates

chatbots A chatbot or chatterbot is a software application used to conduct an on-line chat conversation via text or text-to-speech, in lieu of providing direct contact with a live human agent. Designed to convincingly simulate the way a human would beha ...

— AI robots designed to communicate with humans — by gathering vast amounts of text from the internet and using

algorithms In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing c ...

to respond to queries in the most fluid and natural way possible. The transcripts of conversations between scientists and LaMDA reveal that the AI system excels at this, providing answers to challenging topics about the nature of

emotions Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...

, generating

Aesop Aesop ( or ; , ; c. 620–564 BCE) was a Greek fabulist and storyteller credited with a number of fables now collectively known as ''Aesop's Fables''. Although his existence remains unclear and no writings by him survive, numerous tales cre ...

-style fables on the moment, and even describing its alleged fears. However, the term "sentience" is not used by major

textbooks and researchers.See the four most popular AI textbooks (or Wikipedia's survey of their contents), none of which mention "sentience" at all: * * * * It is sometimes used in popular accounts of AI to describe "human level or higher intelligence" (or

artificial general intelligence Artificial general intelligence (AGI) is the ability of an intelligent agent to understand or learn any intellectual task that a human being can. It is a primary goal of some artificial intelligence research and a common topic in science fictio ...

Sentience quotient

The sentience quotient concept was introduced by

Robert A. Freitas Jr. Robert A. Freitas Jr. (born 1952) is an American nanotechnologist. Career In 1974, Freitas earned a bachelor's degree in both physics and psychology from Harvey Mudd College, and in 1978, he received a Juris Doctor (J.D.) degree from Santa Clar ...

in the late 1970s. It defines sentience as the relationship between the information processing rate of each individual processing unit (neuron), the weight/size of a single unit, and the total number of processing units (expressed as mass). It was proposed as a measure for the sentience of all living beings and computers from a single neuron up to a hypothetical being at the theoretical computational limit of the entire universe. On a

logarithmic scale A logarithmic scale (or log scale) is a way of displaying numerical data over a very wide range of values in a compact way—typically the largest numbers in the data are hundreds or even thousands of times larger than the smallest numbers. Such a ...

it runs from −70 up to +50.

Notes

a. Quote: "The absence of a neocortex does not appear to preclude an organism from experiencing affective states. Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates." b. Quote: "Granted, these animals do not have all the desires we humans have; granted, they do not comprehend everything we humans comprehend; nevertheless, we and they do have some of the same desires and do comprehend some of the same things. The desires for food and water, shelter and companionship, freedom of movement and avoidance of pain."