In a 1927 letter to Sigmund Freud, Romain Rolland coined the phrase "oceanic feeling" to refer to the sensation of being one with the universe. According to Rolland, this feeling is the source of all the religious energy that permeates in various religious systems, and one may justifiably call oneself religious on the basis of this oceanic feeling alone, even if one renounces every belief and every illusion. Freud discusses the feeling in his Future of an Illusion (1927) and Civilization and Its Discontents (1929). There he deems it a fragmentary vestige of a kind of consciousness possessed by an infant who has not yet differentiated himself or herself from other people and things.
On December 5, 1927, Rolland coined the phrase in a letter to Freud:
Mais j'aurais aimé à vous voir faire l'analyse du sentiment religieux spontané ou, plus exactement, de la sensation religieuse qui est (...) le fait simple et direct de la sensation de l'Eternel (qui peut très bien n'être pas éternel, mais simplement sans bornes perceptibles, et comme océanique).
In strict translation:
But I would have liked to see you doing an analysis of spontaneous religious sentiment or, more exactly, of religious feeling, which is (...) the simple and direct fact of the feeling of the ‘eternal’ (which can very well not be eternal, but simply without perceptible limits, and like oceanic, as it were).
Freud ends The Future of an Illusion with a discussion of the concept, and picks up the discussion as the beginning of Civilization and Its Discontents, answering Rolland's request. There he credits the concept to an anonymous friend.
Freud argues that the "oceanic feeling", if it exists, is the preserved "primitive ego-feeling" from infancy. The primitive ego-feeling precedes the creation of the ego and exists up until the mother ceases breastfeeding. Prior to this, the infant is regularly breastfed in response to its crying and has no concept that the breast does not belong to it. Therefore, the infant has no concept of a "self" or, rather, considers the breast to be part of itself. Freud argues that those experiencing an oceanic feeling as an adult are actually experiencing a preserved primitive ego-feeling. The ego, in contrast, comes into existence when the breast is taken away, and involves the infant's recognition that it is separate from the mother's breast, and therefore, that other people exist. Freud argues that it would not necessarily contradict psychoanalytical theory for this primary ego-feeling to coexist along with the ego in some people. The main argument for this is that psychoanalytical theory holds that all thoughts are preserved in a conservation of psychic energy. Therefore, the "oceanic feeling" described as a oneness with the world or a limitlessness is simply a description of the feeling the infant has before it learns there are other persons in the world.
"Neurotheology" is a neologism that describes the scientific study of the neural correlates of religious or spiritual beliefs and practices. Other researchers have rejected the term, preferring to use terms like "spiritual neuroscience" or "neuroscience of religion". Researchers in the field attempt to explain the neurological basis for religious experiences, such as: the perception that time, fear or self-consciousness have dissolved; spiritual awe; oneness with the universe; ecstatic trance; sudden enlightenment; and altered states of consciousness.
- Roberts, Robert (18 November 2016). Zalta, Edward N., ed. "Emotions in the Christian Tradition". Stanford Encyclopedia of Philosophy. Winter 2016.
- The Ontology of Religiosity: The Oceanic Feeling and the Value of the Lived Experience
- Freud, Sigmund. Civilization and Its Discontents, pp. 11–13.
- Masson, Jeffrey Moussaieff (6 December 2012). The Oceanic Feeling. The Origins of Religious Sentiment in Ancient India. Springer Science & Business Media. p. 34. ISBN 978-9-400-98969-6. ISBN 9-40098969-5. 1st ed.: 1980.
- Parsons, William B. (17 June 1999). The Enigma of the Oceanic Feeling. Revisioning the Psychoanalytic Theory of Mysticism. Oxford University Press. p. 36. ISBN 978-0-195-35408-9. ISBN 0-19535408-7.
- Burton, Robert A. (5 February 2008). "Neurotheology". On Being Certain. Believing You Are Right Even When You're Not. New York City: Macmillan Publishers/St. Martin's Press. ISBN 1-42992611-2; ISBN 978-1-429-92611-9 (Macmillan Publishers edition). ISBN 0-31235920-9; ISBN 978-0-312-35920-1 (St. Martin's Press edition).