Cicero coined the term as part of his philosophical construct in 1st-century Rome, but he described it as "a second self, a trusted friend".2
The existence of "another self" was first fully recognized in the 18th century, when Anton Mesmer and his followers used hypnosis to separate the alter ego.3 These experiments showed a behavior pattern that was distinct from the personality of the individual when he was in the waking state compared with when he was under hypnosis. Another character had developed in the altered state of consciousness but in the same body.4
Sigmund Freud, throughout his career, would appeal to such instances of dual consciousness to support his thesis of the unconscious.5 He considered that "We may most aptly describe them as cases of a splitting of the mental activities into two groups, and say that the same consciousness turns to one or the other of these groups alternately".6 Freud considered the roots of the phenomenon of the alter ego to be in the narcissistic stage of early childhood.7 Heinz Kohut would identify a specific need in that early phase for mirroring, by another which resulted later in what he called the "twinship or alter ego transference".8
Glenn Daniel Wilson (1991). Psychology and Performing Arts. Taylor & Francis. ISBN 90-265-1119-1. 90-265-1119-1 ↩
"Alter Ego". Collins English Dictionary - Complete and Unabridged 10th Edition. William Collins Sons & Co. Ltd. 2009. Retrieved 13 January 2013. http://dictionary.reference.com/browse/alter+ego ↩
J Haule, Jung in the 21st Century II (2010) p. 88 ↩
Pedersen, David (1994). Cameral Analysis: A Method of Treating the Psychoneuroses Using Hypnosis. London, U.K.: Routledge. p. 20. ISBN 0-415-10424-6. 0-415-10424-6 ↩
Freud, S., Five Lectures on Psycho-Analysis (Penguin 1995) p. 21 ↩
Freud, S. On Metapsychology (PFL 11) p. 172 ↩
Freud, S., 'The Uncanny' Imago V (1919) p. 41 ↩
Kohut, H., How Does Analysis Cure? (London 1984) p. 192-3 ↩
I. Ousby ed., The Cambridge Guide to Literature in English (Cambridge 1995) p. 263 ↩
N. Douglas, Looking Back (London 1934) p. 274 ↩
Naversen, Ron (2015). "The (Super) Hero's Masquerade". In Bell, Deborah (ed.). Masquerade: Essays on Tradition and Innovation Worldwide. McFarland. pp. 217ff. ISBN 978-0-7864-7646-6. 978-0-7864-7646-6 ↩
Robb, Brian J. (May 2014). A Brief History of Superheroes: From Superman to the Avengers, the Evolution of Comic Book Legends. Hatchet UK. ↩
Kotrial, Utsav (August 30, 2018). "The Origin Stories of Music's Biggest Alter Egos". Rolling Stone. Retrieved November 16, 2019. https://rollingstoneindia.com/origin-stories-musics-biggest-alter-egos/ ↩
"'Ziggy Stardust': How Bowie Created the Alter Ego That Changed Rock". Rolling Stone. Retrieved 19 July 2021. https://www.rollingstone.com/music/music-news/ziggy-stardust-how-bowie-created-the-alter-ego-that-changed-rock-55254/ ↩
Juzwiak, Rich (June 18, 2019). "Madonna: Madame X Album Review". Pitchfork. Retrieved November 16, 2019. https://pitchfork.com/reviews/albums/madonna-madame-x/ ↩