In many religious and philosophical traditions, there is a belief that a soul is "the immaterial aspect or

essence Essence ( la, essentia) is a polysemic term, used in philosophy and theology as a designation for the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it ...

of a human being".

Etymology

The Modern English noun '' soul'' is derived from

Old English Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th c ...

''sāwol, sāwel''. The earliest attestations reported in the '' Oxford English Dictionary'' are from the 8th century. In

King Alfred Alfred the Great (alt. Ælfred 848/849 – 26 October 899) was King of the West Saxons from 871 to 886, and King of the Anglo-Saxons from 886 until his death in 899. He was the youngest son of King Æthelwulf and his first wife Osburh, who ...

's translation of '' De Consolatione Philosophiae'', it is used to refer to the immaterial, spiritual, or thinking aspect of a person, as contrasted with the person's physical body; in the

Vespasian Psalter The Vespasian Psalter (London, British Library, Cotton Vespasian A I) is an Anglo-Saxon illuminated psalter decorated in a partly Insular style produced in the second or third quarter of the 8th century. It contains an interlinear gloss in Old E ...

77.50, it means "life" or "animate existence". The Old English word is cognate with other historical Germanic terms for the same idea, including Old Frisian ''sēle, sēl'' (which could also mean "salvation", or "solemn oath"), Gothic ''saiwala'', Old High German ''sēula, sēla'', Old Saxon ''sēola'', and

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is a stage of development of North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants of Scandinavia and their overseas settlemen ...

''sāla''. Present-day cognates include Dutch ''ziel'' and German ''Seele''.

Religious views

Judaism Judaism ( he, ''Yahăḏūṯ'') is an Abrahamic, monotheistic, and ethnic religion comprising the collective religious, cultural, and legal tradition and civilization of the Jewish people. It has its roots as an organized religion in t ...

and in some Christian denominations, only human beings have immortal souls (although immortality is disputed within Judaism and the concept of immortality was most likely influenced by Plato). For example, Thomas Aquinas, borrowing directly from Aristotle's '' On the Soul'', attributed "soul" ('' anima'') to all organisms but argued that only human souls are immortal. Other religions (most notably Hinduism and Jainism) believe that all living things from the smallest bacterium to the largest of mammals are the souls themselves ( Atman, jiva) and have their physical representative (the body) in the world. The actual self is the soul, while the body is only a mechanism to experience the karma of that life. Thus if one sees a tiger then there is a self-conscious identity residing in it (the soul), and a physical representative (the whole body of the tiger, which is observable) in the world. Some teach that even non-biological entities (such as rivers and mountains) possess souls. This belief is called animism.

Ancient Near East

Souls of Pe and Nekhen towing at Ramses' Temple in Abydos c

In the ancient Egyptian religion, an individual was believed to be made up of various elements, some physical and some spiritual. Similar ideas are found in ancient Assyrian and Babylonian religion. The

Kuttamuwa stele The Kuttamuwa stele is an 800-pound basalt funerary stele with an Aramaic inscription referring to Kuttamuwa, an 8th-century BC royal official. It was found in Sam'al, in southeastern Turkey, in 2008, by the Neubauer Expedition of the Oriental ...

, a funeral stele for an 8th-century BCE royal official from Sam'al, describes Kuttamuwa requesting that his mourners commemorate his life and his afterlife with feasts "for my soul that is in this stele". It is one of the earliest references to a soul as a separate entity from the body. The basalt stele is tall and wide. It was uncovered in the third season of excavations by the Neubauer Expedition of the Oriental Institute in Chicago, Illinois.

Baháʼí Faith

The Baháʼí Faith affirms that "the soul is a sign of God, a heavenly gem whose reality the most learned of men hath failed to grasp, and whose mystery no mind, however acute, can ever hope to unravel". Bahá'u'lláh stated that the soul not only continues to live after the physical death of the human body, but is, in fact, immortal. Heaven can be seen partly as the soul's state of nearness to God; and hell as a state of remoteness from God. Each state follows as a natural consequence of individual efforts, or the lack thereof, to develop spiritually. Bahá'u'lláh taught that individuals have no existence prior to their life here on earth and the soul's evolution is always towards God and away from the material world.

Christianity

According to some Christian eschatology, when people die, their souls will be judged by God and determined to go to Heaven or to Hades awaiting a resurrection or the

resurrection Resurrection or anastasis is the concept of coming back to life after death. In a number of religions, a dying-and-rising god is a deity which dies and is resurrected. Reincarnation is a similar process hypothesized by other religions, whic ...

. The oldest existing branches of Christianity, the

Catholic Church The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

and the

Eastern Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 *Eastern Air Li ...

and Oriental Orthodox churches, adhere to this view, as well as many Protestant denominations. Some Protestant Christians understand the soul as "life,” and believe that the dead have no conscious existence until after the resurrection (

Christian conditionalism In Christian theology, conditionalism or conditional immortality is a concept in which the gift of immortality is attached to (conditional upon) belief in Jesus Christ. This doctrine is based in part upon another biblical argument, that the human ...

). Some Protestant Christians believe that the souls and bodies of the unrighteous will be destroyed in Hell rather than suffering eternally (

annihilationism In Christianity, annihilationism (also known as extinctionism or destructionism) is the belief that after the Last Judgment, all unsaved human beings, all fallen angels (all of the damned) and Satan himself will be totally destroyed so as to not ...

). Believers will inherit eternal life either in Heaven, or in a Kingdom of God on earth, and enjoy eternal fellowship with God. Other Christians reject the punishment of the soul.

Origin of the soul

The "origin of the soul" has provided a vexing question in Christianity. The major theories put forward include soul creationism,

traducianism In Christian theology, traducianism is a doctrine about the origin of the soul holding that this immaterial aspect is transmitted through natural generation along with the body, the material aspect of human beings. That is, human propagation is of ...

, and

pre-existence Pre-existence, preexistence, beforelife, or premortal existence, is the belief that each individual human soul existed before mortal conception, and at some point before birth enters or is placed into the body. Concepts of pre-existence can enc ...

. According to soul creationism, God creates each individual soul directly, either at the moment of conception or some later time. According to traducianism, the soul comes from the parents by natural generation. According to the preexistence theory, the soul exists before the moment of conception. There have been differing thoughts regarding whether human embryos have souls from conception, or whether there is a point between conception and birth where the fetus acquires a soul, consciousness, and/or

personhood Personhood or personality is the status of being a person. Defining personhood is a controversial topic in philosophy and law and is closely tied with legal and political concepts of citizenship, equality, and liberty. According to law, only a l ...

. Stances in this question might play a role in judgements on the

morality of abortion The abortion debate is a longstanding, ongoing controversy that touches on the moral, legal, medical, and religious aspects of induced abortion. In English-speaking countries, the debate most visibly polarizes around adherents of the self-describ ...

Trichotomy of the soul

Augustine (354-430), one of western Christianity's most influential early Christian thinkers, described the soul as "a special substance, endowed with reason, adapted to rule the body". Some Christians espouse a trichotomic view of humans, which characterizes humans as consisting of a body (''soma''), soul (''psyche''), and spirit (''pneuma''). However, the majority of modern Bible scholars point out how the concepts of "spirit" and of "soul" are used interchangeably in many biblical passages, and so hold to dichotomy: the view that each human comprises a body and a soul. Paul said that the "body wars against" the soul, "For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit" (Heb 4:12 NASB), and that "I buffet my body", to keep it under control.

Views of various denominations

; Roman Catholicism The present Catechism of the Catholic Church states that the term soul : “refers to the innermost aspect of ersons that which is of greatest value in

hem A hem in sewing is a garment finishing method, where the edge of a piece of cloth is folded and sewn to prevent unravelling of the fabric and to adjust the length of the piece in garments, such as at the end of the sleeve or the bottom of the g ...

that by which

hey are Hey or Hey! may refer to: Music * Hey (band), a Polish rock band Albums * ''Hey'' (Andreas Bourani album) or the title song (see below), 2014 * ''Hey!'' (Julio Iglesias album) or the title song, 1980 * ''Hey!'' (Jullie album) or the title ...

most especially in God's image: ‘soul’ signifies the spiritual principle in umanity��. All souls living and dead will be judged by Jesus Christ when he comes back to earth. The Catholic Church teaches that the existence of each individual soul is dependent wholly upon God: : "The doctrine of the faith affirms that the spiritual and immortal soul is created immediately by God." Dutch Church Sleepy Hollow 24

;Protestantism Protestants generally believe in the soul's existence and immortality, but fall into two major camps about what this means in terms of an afterlife. Some, following John Calvin, believe that the soul persists as consciousness after death. Others, following Martin Luther, believe that the soul dies with the body, and is unconscious ("sleeps") until the resurrection of the dead. ;Adventism: Various new religious movements deriving from Adventism — including

Christadelphians The Christadelphians () or Christadelphianism are a restorationist and millenarian Christian group who hold a view of biblical unitarianism. There are approximately 50,000 Christadelphians in around 120 countries. The movement developed in the ...

, Seventh-day Adventists, and Jehovah's Witnesses — similarly believe that the dead do not possess a soul separate from the body and are unconscious until the resurrection. ;Latter-day Saints (‘Mormonism’): The Church of Jesus Christ of Latter-day Saints teaches that the spirit and body together constitute the Soul of Man (Mankind). "The spirit and the body are the soul of man." Latter-day Saints believe that the soul is the union of a pre-existing, God-made spirit and a temporal body, which is formed by physical conception on earth. After death, the spirit continues to live and progress in the Spirit world until the

, when it is reunited with the body that once housed it. This reuniting of body and spirit results in a perfect soul that is immortal, and eternal, and capable of receiving a fulness of joy. Latter-day Saint cosmology also describes "intelligences" as the essence of consciousness or agency. These are co-eternal with God, and animate the spirits. The union of a newly-created spirit body with an eternally-existing intelligence constitutes a "spirit birth" and justifies God's title "Father of our spirits".

Confucianism

Some Confucian traditions contrast a spiritual soul with a corporeal soul.

Hinduism

''Ātman'' is a

Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...

word that means inner self or soul. David Lorenzen (2004), The Hindu World (Editors: Sushil Mittal and Gene Thursby), Routledge, , pp. 208–09, Quote: "Advaita and nirguni movements, on the other hand, stress an interior mysticism in which the devotee seeks to discover the identity of individual soul (atman) with the universal ground of being (brahman) or to find god within himself". In Hindu philosophy, especially in the Vedanta school of Hinduism, Ātman is the

first principle In philosophy and science, a first principle is a basic proposition or assumption that cannot be deduced from any other proposition or assumption. First principles in philosophy are from First Cause attitudes and taught by Aristotelians, and nua ...

, the ''true'' self of an individual beyond identification with phenomena, the essence of an individual. In order to attain liberation (moksha), a human being must acquire self-knowledge (atma jnana), which is to realize that one's true self (Ātman) is identical with the transcendent self Brahman according to

Advaita Vedanta ''Advaita Vedanta'' (; sa, अद्वैत वेदान्त, ) is a Hindu sādhanā, a path of spiritual discipline and experience, and the oldest extant tradition of the orthodox Hindu school Vedānta. The term ''Advaita'' ( ...

. The six orthodox schools of Hinduism believe that there is Ātman (self, essence) in every being. K. N. Jayatilleke (2010), Early Buddhist Theory of Knowledge, , pp. 246–49, from note 385 onwards; Steven Collins (1994), Religion and Practical Reason (Editors: Frank Reynolds, David Tracy), State Univ of New York Press, , p. 64; "Central to Buddhist soteriology is the doctrine of not-self (Pali: anattā, Sanskrit: anātman, the opposed doctrine of ātman is central to Brahmanical thought). Put very briefly, this is the uddhistdoctrine that human beings have no soul, no self, no unchanging essence."; Edward Roer (Translator), to ''Brihad Aranyaka Upanishad'', pp. 2–4; Katie Javanaud (2013)
Is The Buddhist ‘No-Self’ Doctrine Compatible With Pursuing Nirvana?
, Philosophy Now In Hinduism and Jainism, a ''jiva'' ( sa, जीव, , alternative spelling ''jiwa''; hi, जीव, , alternative spelling ''jeev'') is a living being, or any entity imbued with a life force. The concept of ''jiva'' in Jainism is similar to '' atman'' in Hinduism. However, some Hindu traditions differentiate between the two concepts, with ''jiva'' considered as individual self, while atman as that which is universal unchanging self that is present in all living beings and everything else as the metaphysical Brahman. The latter is sometimes referred to as ''jiva-atman'' (a soul in a living body).

Islam

The

Quran The Quran (, ; Standard Arabic: , Quranic Arabic: , , 'the recitation'), also romanized Qur'an or Koran, is the central religious text of Islam, believed by Muslims to be a revelation from God. It is organized in 114 chapters (pl.: , s ...

, the holy book of Islam, uses two words to refer to the soul: ''

rūḥ The Holy Spirit ( ar, رُوحُ ٱلْقُدُسِ, ''ruh al-qudus'') is mentioned four times in the Quran, where it acts as an agent of divine action or communication. The Muslim interpretation of the Holy Spirit is generally consistent with o ...

'' (translated as spirit, consciousness, pneuma or "soul") and ''

nafs ''Nafs'' () is an Arabic word occurring in the Quran, literally meaning "self", and has been translated as "psyche", " ego" or " soul".Nurdeen Deuraseh and Mansor Abu Talib (2005), "Mental health in Islamic medical tradition", ''The Internati ...

'' (translated as self, ego, psyche or "soul"), cognates of the Hebrew ''nefesh'' and ''ruach''. The two terms are frequently used interchangeably, though ''rūḥ'' is more often used to denote the divine spirit or "the breath of life", while ''nafs'' designates one's disposition or characteristics. In Islamic philosophy, the immortal rūḥ "drives" the mortal nafs, which comprises temporal desires and perceptions necessary for living. Two of the passages in the Quran that mention the rûh occur in chapters 17 ("The Night Journey") and 39 ("The Troops"):

Jainism

In Jainism, every living being, from plant or bacterium to human, has a soul and the concept forms the very basis of Jainism. According to Jainism, there is no beginning or end to the existence of soul. It is eternal in nature and changes its form until it attains liberation. In Jainism, ''jiva'' is the immortal essence or soul of a living organism (human, animal, fish or plant etc.) which survives physical death. The concept of ''Ajiva'' in Jainism means "not soul", and represents matter (including body), time, space, non-motion and motion. In Jainism, a ''Jiva'' is either ''samsari'' (mundane, caught in cycle of rebirths) or ''mukta'' (liberated). According to this belief until the time the soul is liberated from the '' saṃsāra'' (cycle of repeated birth and death), it gets attached to one of these bodies based on the karma (actions) of the individual soul. Irrespective of which state the soul is in, it has got the same attributes and qualities. The difference between the liberated and non-liberated souls is that the qualities and attributes are manifested completely in case of '' siddha'' (liberated soul) as they have overcome all the karmic bondages whereas in case of non-liberated souls they are partially exhibited. Souls who rise victorious over wicked emotions while still remaining within physical bodies are referred to as arihants. Concerning the Jain view of the soul, Virchand Gandhi said

Judaism

The Hebrew terms '' nefesh'' (literally "living being"), ''

ruach In Judaism, the Holy Spirit ( he, רוח הקודש, ''ruach ha-kodesh'') refers to the divine force, quality, and influence of God over the universe or over God's creatures, in given contexts.Maimonides, Moses. Part II, Ch. 45: "The various c ...

'' (literally "wind"), ''neshamah'' (literally "breath"), ''chayah'' (literally "life") and ''yechidah'' (literally "singularity") are used to describe the soul or spirit. In

the soul is believed to be given by God to Adam as mentioned in Genesis, Judaism relates the quality of one's soul to one's performance of the commandments ('' mitzvot)'' and reaching higher levels of understanding, and thus closeness to God. A person with such closeness is called a '' tzadik''. Therefore, Judaism embraces the commemoration of the day of one's death, '' nahala''/''Yahrtzeit'' and not the

birthday A birthday is the anniversary of the birth of a person, or figuratively of an institution. Birthdays of people are celebrated in numerous cultures, often with birthday gifts, birthday cards, a birthday party, or a rite of passage. Many re ...

as a festivity of remembrance, for only toward the end of life's struggles, tests and challenges could human souls be judged and credited for righteousness. Judaism places great importance on the study of the souls. Kabbalah and other mystic traditions go into greater detail into the nature of the soul. Kabbalah separates the soul into five elements, corresponding to the

five worlds The Four Worlds ( he, עולמות ''Olamot'', singular: ''Olam'' עולם), sometimes counted with a prior stage to make Five Worlds, are the comprehensive categories of spiritual realms in Kabbalah in the descending chain of Existence. The c ...

: # Nefesh, related to natural instinct. #

Ruach In Judaism, the Holy Spirit ( he, רוח הקודש, ''ruach ha-kodesh'') refers to the divine force, quality, and influence of God over the universe or over God's creatures, in given contexts.Maimonides, Moses. Part II, Ch. 45: "The various c ...

, related to intellect and the awareness of God. # Neshamah, related to emotion and morality. # Chayah, considered a part of God, as it were. # Yechidah. This aspect is essentially one with God. Kabbalah also proposed a concept of reincarnation, the '' gilgul''. (See also '' nefesh habehamit'' the "animal soul".) Some Jewish traditions assert that the soul is housed in the ''

luz Luz ( ''Lūz'') is the name of two places in the Bible. Mentioned in Genesis Luz is the ancient name of a royal Canaanite city, connected with Bethel (Genesis 28:19; 35:6). It is debated among scholarsRashi on 28:17 whether Luz and Bethel repres ...

'' bone, though traditions disagree as to whether it is the atlas at the top of the spine, or the sacrum at bottom of the spine.

Scientology

The

Scientology Scientology is a set of beliefs and practices invented by American author L. Ron Hubbard, and an associated movement. It has been variously defined as a cult, a Scientology as a business, business, or a new religious movement. The most recent ...

view is that a person does not have a soul, it is a soul. It is the belief of the religion that they do not have the power to force adherents' conclusions. Therefore, a person is immortal, and may be reincarnated if they wish. Scientologists view that one's future happiness and immortality, as guided by their spirituality, is influenced by how they live and act during their time on earth. The Scientology term for the soul is " thetan", derived from the Greek word "theta", symbolizing thought. Scientology counselling (called auditing) addresses the soul to improve abilities, both worldly and spiritual. The ideologies surrounding this understanding align with those of the five major world religions.

Shamanism

Soul dualism (also called "multiple souls" or "dualistic pluralism") is a common belief in Shamanism, and is essential in the universal and central concept of "soul flight" (also called "soul journey", "

out-of-body experience An out-of-body experience (OBE or sometimes OOBE) is a phenomenon in which a person perceives the world from a location outside their physical body. An OBE is a form of autoscopy (literally "seeing self"), although this term is more commonly us ...

", " ecstasy", or " astral projection"). It is the belief that humans have two or more souls, generally termed the "body soul" (or "life soul") and the "free soul". The former is linked to bodily functions and awareness when awake, while the latter can freely wander during sleep or trance states. In some cases, there are a plethora of soul types with different functions. Soul dualism and multiple souls are prominent in the traditional animistic beliefs of the Austronesian peoples, the Chinese people ( ''hún'' and ''pò''), the Tibetan people, most African peoples, most Native North Americans, ancient

South Asia South Asia is the southern subregion of Asia, which is defined in both geographical Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth descr ...

n peoples, Northern Eurasian peoples, and in Ancient Egyptians (the ''ka'' and ''ba''). The belief in soul dualism is found throughout most Austronesian

shamanistic Shamanism is a religious practice that involves a practitioner (shaman) interacting with what they believe to be a spirit world through altered states of consciousness, such as trance. The goal of this is usually to direct spirits or spiri ...

traditions. The reconstructed

Proto-Austronesian Proto-Austronesian (commonly abbreviated as PAN or PAn) is a proto-language. It is the reconstructed ancestor of the Austronesian languages, one of the world's major language families. Proto-Austronesian is assumed to have begun to diversify ...

word for the "body soul" is ''*nawa'' ("breath", "life", or "vital spirit"). It is located somewhere in the abdominal cavity, often in the liver or the heart (Proto-Austronesian ''*qaCay''). The "free soul" is located in the head. Its names are usually derived from Proto-Austronesian ''*qaNiCu'' ("ghost", "spirit f the dead), which also apply to other non-human nature spirits. The "free soul" is also referred to in names that literally mean "twin" or "double", from Proto-Austronesian ''*duSa'' ("two"). A virtuous person is said to be one whose souls are in harmony with each other, while an evil person is one whose souls are in conflict. The "free soul" is said to leave the body and journey to the spirit world during sleep, trance-like states, delirium, insanity, and death. The duality is also seen in the healing traditions of Austronesian shamans, where illnesses are regarded as a "

soul loss The term loss of soul - In shamanism the term refers to the loss of human part of the life force, soul. Causes of soul loss in shamanism The prevailing concept in traditional shamanism is "any illness is a consequence of a lost or stolen soul ...

" and thus to heal the sick, one must "return" the "free soul" (which may have been stolen by an evil spirit or got lost in the spirit world) into the body. If the "free soul" can not be returned, the afflicted person dies or goes permanently insane. In some ethnic groups, there can also be more than two souls. Like among the

Tagbanwa people The Tagbanwa people (Tagbanwa: ) are one of the oldest ethnic groups in the Philippines, and can be mainly found in the central and northern Palawan. Research has shown that the Tagbanwa are possible descendants of the Tabon Man, thus making th ...

, where a person is said to have six souls – the "free soul" (which is regarded as the "true" soul) and five secondary souls with various functions. Several Inuit groups believe that a person has more than one type of soul. One is associated with respiration, the other can accompany the body as a shadow. In some cases, it is connected to shamanistic beliefs among the various Inuit groups. Also

Caribou Inuit Caribou Inuit ( iu, Kivallirmiut/ᑭᕙᓪᓕᕐᒥᐅᑦ), barren-ground caribou hunters, are Inuit who live west of Hudson Bay in Kivalliq Region, Nunavut, between 61° and 65° N and 90° and 102° W in Northern Canada. They were originally na ...

groups believed in several types of souls. The shaman heals within the spiritual dimension by returning 'lost' parts of the human soul from wherever they have gone. The shaman also cleanses excess negative energies, which confuse or pollute the soul.

Shinto

Shinto distinguishes between the souls of living persons (''tamashii'') and those of dead persons (''

mitama The Japanese word refers to the spirit of a ''kami'' or the soul of a dead person. It is composed of two characters, the first of which, , is simply an honorific. The second, means "spirit". The character pair 神霊, also read ''mitama'', is ...

''), each of which may have different aspects or sub-souls.

Sikhism

Sikhism considers soul (''atma'') to be part of God ( Waheguru). Various hymns are cited from the holy book

Guru Granth Sahib The Guru Granth Sahib ( pa, ਗੁਰੂ ਗ੍ਰੰਥ ਸਾਹਿਬ, ) is the central holy religious scripture of Sikhism, regarded by Sikhs as the final, sovereign and Guru Maneyo Granth, eternal Guru following the lineage of the Sikh gur ...

(SGGS) that suggests this belief. "God is in the Soul and the Soul is in the God." The same concept is repeated at various pages of the SGGS. For example: "The soul is divine; divine is the soul. Worship Him with love." and "The soul is the Lord, and the Lord is the soul; contemplating the Shabad, the Lord is found." The ''atma'' or soul according to Sikhism is an entity or "spiritual spark" or "light" in the human body - because of which the body can sustain life. On the departure of this entity from the body, the body becomes lifeless – no amount of manipulations to the body can make the person make any physical actions. The soul is the "driver" in the body. It is the ''roohu'' or spirit or ''atma'', the presence of which makes the physical body alive. Many religious and philosophical traditions support the view that the soul is the ethereal substance – a spirit; a non-material spark – particular to a unique living being. Such traditions often consider the soul both immortal and innately aware of its immortal nature, as well as the true basis for sentience in each living being. The concept of the soul has strong links with notions of an afterlife, but opinions may vary wildly even within a given religion as to what happens to the soul after death. Many within these religions and philosophies see the soul as immaterial, while others consider it possibly material.

Taoism

According to Chinese traditions, every person has two types of soul called hun and po (魂 and 魄), which are respectively yang and yin.

Taoism Taoism (, ) or Daoism () refers to either a school of philosophical thought (道家; ''daojia'') or to a religion (道教; ''daojiao''), both of which share ideas and concepts of Chinese origin and emphasize living in harmony with the '' Ta ...

believes in ten souls, ''sanhunqipo'' ( 三魂七魄) "three ''hun'' and seven ''po''". A living being that loses any of them is said to have mental illness or unconsciousness, while a dead soul may reincarnate to a disability, lower desire realms, or may even be unable to reincarnate.

Zoroastrianism

Other religious beliefs and views

In theological reference to the soul, the terms "life" and "death" are viewed as emphatically more definitive than the common concepts of " biological life" and "biological death". Because the soul is said to be transcendent of the '' material existence,'' and is said to have (potentially) eternal life, the death of the soul is likewise said to be an ''eternal death''. Thus, in the concept of

divine judgment Divine judgment means the judgment of God or other supreme beings within a religion. Ancient beliefs In ancient Sumerian religion, the sun-god Utu and his twin sister Inanna were believed to be the enforcers of divine justice. Utu, as ...

, God is commonly said to have options with regard to the dispensation of souls, ranging from Heaven (i.e., angels) to hell (i.e., demons), with various concepts in between. Typically both Heaven and hell are said to be eternal, or at least far beyond a typical human concept of lifespan and time. According to Louis Ginzberg, the soul of Adam is the image of

God In monotheistic thought, God is usually viewed as the supreme being, creator, and principal object of faith. Swinburne, R.G. "God" in Honderich, Ted. (ed)''The Oxford Companion to Philosophy'', Oxford University Press, 1995. God is typically ...

. Every soul of human also escapes from the body every night, rises up to heaven, and fetches new life thence for the body of man.

Spirituality, New Age, and new religions

Brahma Kumaris

Brahma Kumaris The Brahma Kumaris are a spiritual movement that originated in Hyderabad, Sindh, during the 1930s.eternal. God is considered to be the Supreme Soul, with maximum degrees of spiritual qualities, such as peace, love and purity.

Theosophy

In Helena Blavatsky's Theosophy, the soul is the field of our psychological activity (thinking, emotions, memory, desires, will, and so on) as well as of the so-called paranormal or

psychic A psychic is a person who claims to use extrasensory perception (ESP) to identify information hidden from the normal senses, particularly involving telepathy or clairvoyance, or who performs acts that are apparently inexplicable by natural laws ...

phenomena (extrasensory perception, out-of-body experiences, etc.). However, the soul is not the highest, but a middle dimension of human beings. Higher than the soul is the spirit, which is considered to be the real self; the source of everything we call "good"—happiness, wisdom, love, compassion, harmony, peace, etc. While the spirit is eternal and incorruptible, the soul is not. The soul acts as a link between the material body and the spiritual self, and therefore shares some characteristics of both. The soul can be attracted either towards the spiritual or towards the material realm, being thus the "battlefield" of good and evil. It is only when the soul is attracted towards the spiritual and merges with the Self that it becomes eternal and divine.

Anthroposophy

Rudolf Steiner Rudolf Joseph Lorenz Steiner (27 or 25 February 1861 – 30 March 1925) was an Austrian occultist, social reformer, architect, esotericist, and claimed clairvoyant. Steiner gained initial recognition at the end of the nineteenth century as ...

claimed classical trichotomic stages of soul development, which interpenetrated one another in consciousness: * The "sentient soul", centering on sensations, drives, and passions, with strong conative (will) and emotional components; * The "intellectual" or "mind soul", internalizing and reflecting on outer experience, with strong affective (feeling) and cognitive (thinking) components; and * The "consciousness soul", in search of universal, objective truths.

Miscellaneous

In Surat Shabda Yoga, the soul is considered to be an exact replica and spark of the Divine. The purpose of Surat Shabd Yoga is to realize one's True Self as soul (Self-Realisation), True Essence (Spirit-Realisation) and True Divinity (God-Realisation) while living in the physical body. Similarly, the spiritual teacher

Meher Baba Meher Baba (born Merwan Sheriar Irani; 25 February 1894 – 31 January 1969) was an Indian spiritual master who said he was the Avatar, or God in human form, of the age. A major spiritual figure of the 20th century, he had a following of ...

held that "Atma, or the soul, is in reality identical with Paramatma the Oversoul – which is one, infinite, and eternal... nd e sole purpose of creation is for the soul to enjoy the infinite state of the Oversoul consciously." Eckankar, founded by Paul Twitchell in 1965, defines Soul as the true self; the inner, most sacred part of each person.

G.I. Gurdjieff George Ivanovich Gurdjieff (; rus, Гео́ргий Ива́нович Гурджи́ев, r=Geórgy Ivánovich Gurdzhíev, p=ɡʲɪˈorɡʲɪj ɪˈvanəvʲɪd͡ʑ ɡʊrd͡ʐˈʐɨ(j)ɪf; hy, Գեորգի Իվանովիչ Գյուրջիև; c. 1 ...

taught that humans are not born with immortal souls but could develop them through certain efforts.

Philosophical views

Greek philosophers, such as Socrates,

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

, and Aristotle, understood that the soul (ψυχή '' psykhḗ'') must have a logical faculty, the exercise of which was the most divine of human actions. At his defense trial, Socrates even summarized his teachings as nothing other than an exhortation for his fellow Athenians to excel in matters of the psyche since all bodily goods are dependent on such excellence ('' Apology'' 30a–b). Aristotle reasoned that a man's body and soul were his matter and form respectively: the body is a collection of elements and the soul is the essence. Soul or

psyche Psyche (''Psyché'' in French) is the Greek term for "soul" (ψυχή). Psyche may also refer to: Psychology * Psyche (psychology), the totality of the human mind, conscious and unconscious * ''Psyche'', an 1846 book about the unconscious by Car ...

(

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

: ψυχή ''psykhḗ'', of ψύχειν ''psýkhein'', "to breathe", cf.

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

'anima') comprises the mental abilities of a living being: reason, character,

free will Free will is the capacity of agents to choose between different possible courses of action unimpeded. Free will is closely linked to the concepts of moral responsibility, praise, culpability, sin, and other judgements which apply only to ac ...

, feeling, consciousness,

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'' () ...

, memory, perception, thinking, etc. Depending on the philosophical system, a soul can either be mortal or

immortal Immortality is the ability to live forever, or eternal life. Immortal or Immortality may also refer to: Film * ''The Immortals'' (1995 film), an American crime film * ''Immortality'', an alternate title for the 1998 British film ''The Wisdom of ...

. The ancient Greeks used the word " ensouled" to represent the concept of being "alive", indicating that the earliest surviving western philosophical view believed that the soul was that which gave the body life. The soul was considered the incorporeal or spiritual "breath" that animates (from the Latin, '' anima'', cf. "animal") the living organism. Francis M. Cornford quotes Pindar by saying that the soul sleeps while the limbs are active, but when one is sleeping, the soul is active and reveals "an award of joy or sorrow drawing near" in dreams.

Erwin Rohde Erwin Rohde (; 9 October 1845 – 11 January 1898) was one of the great German classical scholars of the 19th century. Rohde was born in Hamburg and was the son of a doctor. Outside of antiquarian circles, Rohde is known today chiefly for h ...

writes that an early pre-

Pythagorean Pythagorean, meaning of or pertaining to the ancient Ionian mathematician, philosopher, and music theorist Pythagoras, may refer to: Philosophy * Pythagoreanism, the esoteric and metaphysical beliefs purported to have been held by Pythagoras * Ne ...

belief presented the soul as lifeless when it departed the body, and that it retired into Hades with no hope of returning to a body. Plato was the first thinker in antiquity to combine the various functions of the soul into one coherent conception: the soul is that which moves things (i.e., that which gives life, on the view that life is self-motion) by means of its thoughts, requiring that it be both a mover and a thinker.Campbell, Douglas (2021). "Self‐Motion and Cognition: Plato's Theory of the Soul". ''The Southern Journal of Philosophy''. 59: 523–544.

Socrates and Plato

Drawing on the words of his teacher Socrates, Plato considered the psyche to be the

of a person, being that which decides how we behave. He considered this essence to be an incorporeal, eternal occupant of our being. Plato said that even after death, the soul exists and is able to think. He believed that as bodies die, the soul is continually reborn (

metempsychosis Metempsychosis ( grc-gre, μετεμψύχωσις), in philosophy, is the Reincarnation#Conceptual definitions, transmigration of the soul, especially its reincarnation after death. The term is derived from ancient Greek philosophy, and has be ...

) in subsequent bodies. However, Aristotle believed that only one part of the soul was immortal, namely the intellect ('' logos''). The Platonic soul consists of three parts: # the ''logos'', or ''logistikon'' (mind, nous, or

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, ...

) # the '' thymos'', or ''thumetikon'' (

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

, spiritedness, or masculine) # the ''

eros In Greek mythology, Eros (, ; grc, Ἔρως, Érōs, Love, Desire) is the Greek god of love and sex. His Roman counterpart was Cupid ("desire").''Larousse Desk Reference Encyclopedia'', The Book People, Haydock, 1995, p. 215. In the ear ...

'', or ''epithumetikon'' (appetitive, desire, or feminine) The parts are located in different regions of the body: # ''logos'' is located in the head, is related to reason and regulates the other part. # ''thymos'' is located near the chest region and is related to anger. # ''eros'' is located in the stomach and is related to one's desires. Plato also compares the three parts of the soul or psyche to a societal caste system. According to Plato's theory, the three-part soul is essentially the same thing as a state's class system because, to function well, each part must contribute so that the whole functions well. Logos keeps the other functions of the soul regulated. The soul is at the heart of Plato's philosophy. Francis Cornford described the twin pillars of Platonism as being the theory of the Forms, on the one hand, and, on the other hand, the doctrine of the immortality of the soul. Indeed, Plato was the first person in the history of philosophy to believe that the soul was both the source of life and the mind. In Plato's dialogues, we find the soul playing many disparate roles. Among other things, Plato believes that the soul is what gives life to the body (which was articulated most of all in the ''Laws'' and ''Phaedrus'') in terms of self-motion: to be alive is to be capable of moving yourself; the soul is a self-mover. He also thinks that the soul is the bearer of moral properties (i.e., when I am virtuous, it is my soul that is virtuous as opposed to, say, my body). The soul is also the mind: it is that which thinks in us. We see this casual oscillation between different roles of the soul in many dialogues. First of all, in the ''Republic'':

Is there any function of the soul that you could not accomplish with anything else, such as taking care of something (''epimeleisthai''), ruling, and deliberating, and other such things? Could we correctly assign these things to anything besides the soul, and say that they are characteristic (''idia'') of it? No, to nothing else. What about living? Will we deny that this is a function of the soul? That absolutely is.

The ''Phaedo'' most famously caused problems to scholars who were trying to make sense of this aspect of Plato's theory of the soul, such as Sarah Broadie and Dorothea Frede. More-recent scholarship has overturned this accusation by arguing that part of the novelty of Plato's theory of the soul is that it was the first to unite the different features and powers of the soul that became commonplace in later ancient and medieval philosophy. For Plato, the soul moves things by means of its thoughts, as one scholar puts it, and accordingly, the soul is both a mover (i.e., the principle of life, where life is conceived of as ''self-motion'') and a thinker.

Aristotle

Aristotle (384–322 BCE) defined the soul, or ''Psūchê'' (ψυχή), as the "

first actuality ''Actus primus'', or first actuality, is a technical expression used in scholastic philosophy. The Latin word ''actus'' means determination, complement. In every being there are many actualities, which are subordinated. Thus existence supposes ...

" of a naturally organized body, and argued against its separate existence from the physical body. In Aristotle's view, the primary activity, or full actualization, of a living thing constitutes its soul. For example, the full actualization of an eye, as an independent organism, is to see (its purpose or

final cause The four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?", in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote th ...

). Another example is that the full actualization of a human being would be living a fully functional human life in accordance with reason (which he considered to be a faculty unique to humanity). For Aristotle, the soul is the organization of the form and matter of a natural being which allows it to strive for its full actualization. This organization between form and matter is necessary for any activity, or functionality, to be possible in a natural being. Using an artifact (non-natural being) as an example, a house is a building for human habituation, but for a house to be actualized requires the material (wood, nails, bricks, etc.) necessary for its actuality (i.e. being a fully functional house). However, this does not imply that a house has a soul. In regards to artifacts, the source of motion that is required for their full actualization is outside of themselves (for example, a builder builds a house). In natural beings, this source of motion is contained within the being itself. Aristotle elaborates on this point when he addresses the faculties of the soul. The various

faculties of the soul The faculties of the soul are the individual characteristics attributed to a soul. There have been different attempts to define them over the centuries. Plato, Aristotle and their followers Plato defined the faculties of the soul in terms of a th ...

, such as nutrition, movement (peculiar to animals), reason (peculiar to humans), sensation (special, common, and incidental) and so forth, when exercised, constitute the "second" actuality, or fulfillment, of the capacity to be alive. For example, someone who falls asleep, as opposed to someone who falls dead, can wake up and live their life, while the latter can no longer do so. Aristotle identified three hierarchical levels of natural beings: plants, animals, and people, having three different degrees of soul: ''Bios'' (life), ''Zoë'' (animate life), and ''Psuchë'' (self-conscious life). For these groups, he identified three corresponding levels of soul, or biological activity: the nutritive activity of growth, sustenance and reproduction which all life shares (''Bios''); the self-willed motive activity and sensory faculties, which only animals and people have in common (''Zoë''); and finally "reason", of which people alone are capable (''Pseuchë''). Aristotle's discussion of the soul is in his work, ''De Anima'' ('' On the Soul''). Although mostly seen as opposing Plato in regard to the immortality of the soul, a controversy can be found in relation to the fifth chapter of the third book: in this text both interpretations can be argued for, soul as a whole can be deemed mortal, and a part called "active intellect" or "active mind" is immortal and eternal. Advocates exist for both sides of the controversy, but it has been understood that there will be permanent disagreement about its final conclusions, as no other Aristotelian text contains this specific point, and this part of ''De Anima'' is obscure. Further, Aristotle states that the soul helps humans find the truth, and understanding the true purpose or role of the soul is extremely difficult.

Avicenna and Ibn al-Nafis

Following Aristotle, Avicenna (Ibn Sina) and Ibn al-Nafis, an Arab physician, further elaborated upon the Aristotelian understanding of the soul and developed their own theories on the soul. They both made a distinction between the soul and the spirit, and the Avicennian doctrine on the nature of the soul was influential among the

Scholastics Scholasticism was a medieval school of philosophy that employed a critical organic method of philosophical analysis predicated upon the Aristotelian 10 Categories. Christian scholasticism emerged within the monastic schools that translate ...

. Some of Avicenna's views on the soul include the idea that the immortality of the soul is a consequence of its nature, and not a purpose for it to fulfill. In his theory of "The Ten Intellects", he viewed the human soul as the tenth and final intellect. While he was imprisoned, Avicenna wrote his famous " Floating man" thought experiment to demonstrate human self-awareness and the substantial nature of the soul. He told his readers to imagine themselves suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. He argues that in this scenario one would still have

self-consciousness Self-consciousness is a heightened sense of awareness of oneself. It is not to be confused with consciousness in the sense of qualia. Historically, "self-consciousness" was synonymous with "self-awareness", referring to a state of awareness that ...

. He thus concludes that the idea of the self is not logically dependent on any physical

thing Thing or The Thing may refer to: Philosophy * An object * Broadly, an entity * Thing-in-itself (or ''noumenon''), the reality that underlies perceptions, a term coined by Immanuel Kant * Thing theory, a branch of critical theory that focuse ...

, and that the soul should not be seen in

relative term A relative term is a term that makes two or more distinct references to objects (which may be the same object, for example in "The Morning Star is the Evening Star"). A relative term is typically expressed in ordinary language by means of a phrase ...

s, but as a primary given, a substance. This argument was later refined and simplified by René Descartes in epistemic terms, when he stated: "I can abstract from the supposition of all external things, but not from the supposition of my own consciousness." Avicenna generally supported Aristotle's idea of the soul originating from the heart, whereas Ibn al-Nafis rejected this idea and instead argued that the soul "is related to the entirety and not to one or a few organs". He further criticized Aristotle's idea whereby every unique soul requires the existence of a unique source, in this case the heart. Al-Nafis concluded that "the soul is related primarily neither to the spirit nor to any organ, but rather to the entire matter whose temperament is prepared to receive that soul," and he defined the soul as nothing other than "what a human indicates by saying " I".

Thomas Aquinas

Following Aristotle (whom he referred to as "the Philosopher") and Avicenna, Thomas Aquinas (1225–74) understood the soul to be the first actuality of the living body. Consequent to this, he distinguished three orders of life: plants, which feed and grow; animals, which add sensation to the operations of plants; and humans, which add intellect to the operations of animals. Concerning the human soul, his epistemological theory required that, since the knower becomes what he knows, the soul is definitely not corporeal—if it is corporeal when it knows what some corporeal thing is, that thing would come to be within it. Therefore, the soul has an operation which does not rely on a body organ, and therefore the soul can exist without a body. Furthermore, since the rational soul of human beings is a subsistent form and not something made of matter and form, it cannot be destroyed in any natural process. The full argument for the

immortality of the soul Christian mortalism is the Christian belief that the human soul is not naturally immortal and may include the belief that the soul is “sleeping” after death until the Resurrection of the Dead and the Last Judgment, a time known as the inte ...

and Aquinas' elaboration of Aristotelian theory is found in Question 75 of the First Part of the

Summa Theologica The ''Summa Theologiae'' or ''Summa Theologica'' (), often referred to simply as the ''Summa'', is the best-known work of Thomas Aquinas (1225–1274), a scholastic theologian and Doctor of the Church. It is a compendium of all of the main th ...

. Aquinas affirmed in the doctrine of the divine effusion of the soul, the particular judgement of the soul after the separation from a dead body, and the final Resurrection of the flesh. He recalled two canons of the 4th-century '' De Ecclesiasticis Dogmatibus'' for which "the rational soul is not engendered by coition" (canon XIV) and "is one and the same soul in man, that both gives life to the body by being united to it, and orders itself by its own reasoning." Moreover, he believed in a unique and tripartite soul, within which are distinctively present a nutritive, a sensitive and intellectual soul. The latter is created by God and is taken solely by human beings, includes the other two types of soul and makes the sensitive soul incorruptible.

Immanuel Kant

In his discussions of rational psychology, Immanuel Kant (1724–1804) identified the soul as the "I" in the strictest sense, and argued that the existence of inner experience can neither be proved nor disproved. It is from the "I", or soul, that Kant proposes transcendental rationalization, but cautions that such rationalization can only determine the limits of knowledge if it is to remain practical.

Philosophy of mind

Gilbert Ryle's

ghost in the machine The "ghost in the machine" is a term originally used to describe and critique the notion of the mind existing alongside and separate to the body. In more recent times, the term has several uses, including the concept that the intellectual part of ...

argument, which is a rejection of Descartes's

mind–body dualism In the philosophy of mind, mind–body dualism denotes either the view that mental phenomena are non-physical, Hart, W. D. 1996. "Dualism." pp. 265–267 in ''A Companion to the Philosophy of Mind'', edited by S. Guttenplan. Oxford: Blackwell. ...

, can provide a contemporary understanding of the soul/mind, and the problem concerning its connection to the brain/body.

Psychology

Soul belief prominently figues in

Otto Rank Otto Rank (; ; né Rosenfeld; 22 April 1884 – 31 October 1939) was an Austrian psychoanalyst, writer, and philosopher. Born in Vienna, he was one of Sigmund Freud's closest colleagues for 20 years, a prolific writer on psychoanalytic themes, ...

's work recovering the importance of immortality in the psychology of primitive, classical and modern interest in life and death. Rank's work directly opposed the "scientific" psychology that concedes the possibility of the soul's existence and postulates it as an object of research without really admitting that it exists. "Just as religion represents a psychological commentary on the social evolution of man, various psychologies represent our current attitudes toward spiritual belief. In the animistic era, psychologizing was a ''creating'' of the soul; in the religious era, it was a ''representing'' of the soul to one's self; in our era of natural science it is a ''knowing'' of the individual soul." Rank's "Seelenglaube" translates to "Soul Belief". Rank's work had a significant influence on Ernest Becker's understanding of a universal interest in immortality. In Denial of Death, Becker describes "soul" in terms of Kierkegaard's use of "self" when he says, "what we call schizophrenia is an attempt by the symbolic self to deny the limitations of the finite body."

Science

According to Julien Musolino, the vast majority of scientists hold that the mind is a complex machine that operates on the same physical laws as all other objects in the universe. According to Musolino, there is currently no scientific evidence whatsoever to support the existence of the soul. The search for the soul, however, is seen to have been instrumental in driving the understanding of the anatomy and physiology of the human body, particularly in the fields of cardiovascular and neurology. In the two dominant conflicting concepts of the soul – one seeing it to be spiritual and immortal, and the other seeing it to be material and mortal, both have described the soul as being located in a particular organ or as pervading the whole body.

Neuroscience

Neuroscience as an interdisciplinary field, and its branch of

cognitive neuroscience Cognitive neuroscience is the scientific field that is concerned with the study of the biological processes and aspects that underlie cognition, with a specific focus on the neural connections in the brain which are involved in mental process ...

particularly, operates under the

ontological In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality. Ontology addresses questions like how entities are grouped into categories and which of these entities exi ...

assumption of physicalism. In other words, it assumes that only the fundamental phenomena studied by

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

exist. Thus, neuroscience seeks to understand mental phenomena within the framework according to which human thought and behavior are caused solely by physical processes taking place inside the brain, and it operates by the way of reductionism by seeking an explanation for the mind in terms of brain activity. To study the mind in terms of the brain several methods of

functional neuroimaging Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions. It is primarily used a ...

are used to study the neuroanatomical correlates of various

cognitive processes Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...

that constitute the mind. The evidence from brain imaging indicates that all processes of the mind have physical correlates in brain function. However, such correlational studies cannot determine whether neural activity plays a causal role in the occurrence of these cognitive processes ( correlation does not imply causation) and they cannot determine if the neural activity is either necessary or sufficient for such processes to occur. Identification of causation, and of necessary and sufficient conditions requires explicit experimental manipulation of that activity. If manipulation of brain activity changes consciousness, then a causal role for that brain activity can be inferred. Two of the most common types of manipulation experiments are loss-of-function and gain-of-function experiments. In a loss-of-function (also called "necessity") experiment, a part of the nervous system is diminished or removed in an attempt to determine if it is necessary for a certain process to occur, and in a gain-of-function (also called "sufficiency") experiment, an aspect of the nervous system is increased relative to normal. Manipulations of brain activity can be performed with direct

electrical brain stimulation Electrical brain stimulation (EBS), also referred to as focal brain stimulation (FBS), is a form of electrotherapy used as a technique in research and clinical neurobiology to stimulate a neuron or neural network in the brain through the direc ...

, magnetic brain stimulation using

transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse gener ...

, psychopharmacological manipulation, optogenetic manipulation, and by studying the symptoms of brain damage (case studies) and lesions. In addition, neuroscientists are also investigating how the mind develops with the development of the brain.

Physics

Physicist Sean M. Carroll has written that the idea of a soul is incompatible with quantum field theory (QFT). He writes that for a soul to exist: "Not only is new physics required, but dramatically new physics. Within QFT, there can't be a new collection of 'spirit particles' and 'spirit forces' that interact with our regular atoms, because we would have detected them in existing experiments." Quantum indeterminism has been invoked as an explanatory mechanism for possible soul/brain interaction, but neuroscientist Peter Clarke found errors with this viewpoint, noting there is no evidence that such processes play a role in brain function; Clarke concluded that a Cartesian soul has no basis from quantum physics.

Parapsychology

Some

parapsychologists Parapsychology is the study of alleged psychic phenomena (extrasensory perception, telepathy, precognition, clairvoyance, psychokinesis (also called telekinesis), and psychometry) and other paranormal claims, for example, those related to near ...

have attempted to establish, by

scientific Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

experiment, whether a soul separate from the brain exists, as is more commonly defined in religion rather than as a synonym of psyche or mind.

Milbourne Christopher Milbourne Christopher (23 March 1914 – 17 June 1984) was a prominent American illusionist, magic historian, and author. President of the Society of American Magicians, an honorary vice-president to The Magic Circle, and one of the founding m ...

(1979) and Mary Roach (2010) have argued that none of the attempts by parapsychologists have yet succeeded.

Weight of the soul

In 1901 Duncan MacDougall conducted an experiment in which he made weight measurements of patients as they died. He claimed that there was weight loss of varying amounts at the time of death; he concluded the soul weighed 21 grams, based on measurements of a single patient and discarding conflicting results. The physicist Robert L. Park wrote that MacDougall's experiments "are not regarded today as having any scientific merit" and the psychologist Bruce Hood wrote that "because the weight loss was not reliable or replicable, his findings were unscientific." Hood, Bruce. (2009). ''Supersense: From Superstition to Religion – The Brain Science of Belief''. Constable. p. 165.