Sentience is the ability to feel or perceive subjectively. It is an important concept in the philosophy of
animal rights, in buddhist philosophy and in science fiction, although in each of these fields the term is used slightly differently. Sentience is sometimes also used in philosophyas one aspect of the important idea of consciousness.
Non-human animal rights and sentience
philosophyof animal rights, sentience is commonly seen as the ability to experience suffering. Animal rights advocates argue that anything which can suffer is sentient and anything which is sentient has the same or similar rights as a human being.
In the 17th century
Thomas Tryon, a self-identified Pythagorean, raised the issue of non-human suffering. Soon thereafter, many philosophers used the anatomical discoveries of the Enlightenmentas a reason to include animals in what philosophers call "sympatheia," the principle of who or what deserves sympathy. Benjamin Franklin's autobiography identifies Tryon's writings as an influence in his decision to try vegetarianism; no other part of the book mentions his reverting back to eating meat. [ [http://www.earlyamerica.com/lives/franklin/chapt1/index.html Ben Franklin, autobiography] ] Joseph Ritsoncoupled Tryon's work with Rousseau's for "Essay on Abstinence from Animal Food" as many Rousseauists became vegetarian. Voltairecompared the Hindu treatment of animals to how Europe's emperors & Popes treated even their fellow men, praising the former and heaping shame upon the latter; in the 17th century, Descartes, Pierre Gassendi, and Francis Baconalso advocated vegetarianism. [ [http://www.guardian.co.uk/books/2006/aug/21/extract Guardian (UK) newspaper, review of Bloodless Revolution, published by Harper-Collins] ]
The 18th century philosopher
Jeremy Benthamcompiled Enlightenment beliefs in " [http://www.la.utexas.edu/research/poltheory/bentham/ipml/index.html An Introduction to the Principles of Morals and Legislation] ", and he included his own reasoning in a comparison between slavery and sadism toward animals:
In the 20th century, Princeton University professor
Peter Singerargues that Bentham's conclusion is often dismissed by an appeal to a distinction that condemns human suffering but allows non-human suffering, typically "appeals" that are logical fallacies. Because many of the suggested distinguishing features of humanity -- extreme intelligence; highly complex language; etc. -- are not present in marginal cases such as young or mentally disabled humans, it appears that the only distinction is a prejudice based on species alone, which non-human animal rights supporters call speciesism- that is, differentiating humans from other animals purely on the grounds that they are human. Gary Francionealso bases his abolitionist 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." [Francione, Gary. [http://www.abolitionistapproach.com/?page_id=52 Official blog] ] Andrew Linzey, founder of the Oxford Centre for Animal Ethics in England, is known as a foremost international advocate for recognizing animals as sentient beings in Biblically-based faith traditions. The Interfaith Association of Animal Chaplainsencourages animalministry groups to adopt a policy of recognizing and valuing sentient beings.
science fiction, an alien, android, robot, hologramor computerwho is described as "sentient" is often ascribed qualities such as will, desire, consciousness, ethics, personality, intelligence, insight, and so on. Sentience is being used in this context to describe an essential human property that brings all these other qualities with it.
Some science fiction plot lines explore ethical concerns, analogous to the concerns of advocates of
animal rights. In an episode of ', "The Measure of a Man," Data, a sentient android, takes legal action to prove that he has the same rights as a human being. In the episode "Author, Author" the Doctor, a holographic program by nature, Fights for his rights as a sentient lifeform. The film ' considers a machine in the form of a small boy which has been given the ability to feel human emotions, including the capacity to suffer. Another example could be the film " WALL-E", where the titular character is an initially non-sentient robot who develops sentience over the 700 years he has been active. Other robots in the film also display similar signs of personality.
In many science fiction works sentience is often used as a synomym for "
sapience" meaning "human-level or higher intelligence". But others make a distinction, for example in David Brin's Uplift stories the Tanduare undoubtedly sapient (both technologically skilled and cunning) but only marginally sentient, since they regard other races and sometimes other Tandu mainly as potential prey.Fact|date=May 2008
Eastern religions including
Hinduism, Buddhism, Sikhism, and Jainismrecognize nonhumans as sentient beings. In Jainism and Hinduism, this is closely related to the concept of ahimsa, nonviolence toward other beings. In Jainism, all matter is endowed with sentience; there are six degrees of sentience, from one to six.Fact|date=August 2008 Water, for example, is a sentient being of first order, as it is considered to possess only one sense, that of touch. Man is considered to be sentient being of the sixth order. According to Buddhism, sentient beings made of pure consciousness are possible. In MahayanaBuddhism, which includes Zenand Tibetan Buddhism, the concept is related to the Bodhisattva, an enlightened being devoted to the liberation of others. The first vow of a Bodhisattva states: "Sentient beings are numberless; I vow to free them."
Sentience is, from a Buddhist perspective, the state of having senses (sat + ta in Pali or sat + tva in Sanskrit). In Buddhism, the senses are six in number, the sixth being the mind or consciousness, just as consciousness is in the whole body. [Sugunasiri, Suwanda H J, The Whole Body, not Heart, as 'Seat of Consciousness': the Buddha's View', Philosophy East & West, vol. 45, no. 3, pp. 409-430] Sentience, then, is the ability to sense / experience pain and pleasure, make conscious choices, such as abstaining from action, speech, speculation, etc. Thus, while an animal qualifies as a sentient being, a computer doesn't, for at least two reasons: (a) Even if it makes intelligent decisions (which no computer will ever be capable of without sentience), it has to be programmed by an outside agent (human or even a super-computer), whereas a sentient being is self-directed, and (b) a computer must always perform using instructions in order to communicate, whereas a sentient being, can still express in silence - through kinesics (body lanaguage), oculesics (eye language) and proxemics (distance).
Philosophy and sentience
In the philosophy of
consciousness, "sentience" can refer to the human ability to have subjective perceptual experiences, or " qualia". [Harvnb|Cole|1983] This is distinct from other aspects of the mindand consciousness, such as creativity, intelligence, sapience, self-awarenessand intentionality(the ability to have thoughts that mean something or are "about" something).
Some philosophers, notably
Colin McGinn, believe that sentience will never be understood, a position known as New Mysterianism. They do not deny that most other aspects of consciousnessare subject to scientific investigation but they argue that subjective experiences will never be explained; it is precisely sentience that cannot be explained. Other philosophers (such as Daniel Dennett) disagree, arguing that all aspects of consciousness will eventually yield to scientific investigation.
Sentience Quotientconcept was introduced by Robert A. Freitas Jr.in the late 1970s. [Dr. Freitas, Robert A. Jr., " [http://www.rfreitas.com/Astro/Xenopsychology.htm Xenopsychology] ", Analog Science Fiction/Science Fact, Vol. 104, April 1984, pp 41-53] 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 beings living and computer from a single neuron up to a hypothetical being at the theoretical computational limit of the entire universe. On a logarithmic scaleit runs from -70 up to +50.
entience vs. Sapience
The word "sentient" is often confused with the word "sapient", which can connote
knowledge, consciousness, or apperception. The root of the confusion is that the word "conscious" has a number of different usages in the English language. The two words can be distinguished by looking at their Latinroots: "sentire", "to feel"; and "sapere", "to know." Thus, sentience is a subjective experience, while sapience is a somewhat more objective cognitive ability.
* Sugunasiri, Suwanda H J, The Whole Body, not Heart, as 'Seat of Consciousness': the Buddha's View', Philosophy East & West, vol. 45, no. 3, pp. 409-430). Prof. Sugunasiri is Founder of Nalanda College of Buddhist Studies, Toronto, Canada
* [http://www.la.utexas.edu/research/poltheory/bentham/ipml/index.html Jeremy Bentham - Introduction to the Principles of Morals and Legislation]
* [http://www.oup.com/uk/catalogue/?ci=9780198238515 Book about A Theory of Sentience] Readership: Philosophers, psychologists, and neuroscientists interested in sensation and perception. Authors, Austen Clark, Professor of Philosophy, University of Connecticut, Storrs
* [http://www.d.umn.edu/~dcole/sense5.html D. Cole: Sense and Sentience SENSE5 8/18/90; rev. 1-19-98. (original 1983) copyright David Cole University of Minnesota, Duluth]
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