word forming element indicating "oneself," also "automatic," from Old English use of self (pron.) in compounds, such as selfbana "suicide," selflice "self-love, pride, vanity, egotism," selfwill "free will." Middle English had self-witte "one's own knowledge and intelligence" (early 15c.).
OED counts 13 such compounds in Old English. Middle English Compendium lists four, counting the self-will group as a whole. It re-emerges as a living word-forming element mid-16c., "probably to a great extent by imitation or reminiscence of Greek compounds in (auto-)," and formed a great many words in the pamphlet disputes of the 17c.
early 15c., decepcioun, "act of misleading, a lie, a falsehood," from Old French déception (13c., decepcion) or directly from Late Latin deceptionem (nominative deceptio) "a deceiving," noun of state or action from past-participle stem of Latin decipere "to ensnare, take in, beguile, cheat," from de "from" or pejorative (see de-) + capere "to take," from PIE root *kap- "to grasp."
From mid-15c. as "state of being deceived; error, mistake;" from 1794 as "artifice, cheat, that which deceives."
<a href="https://www.etymonline.com/word/self-deception">Etymology of self-deception by etymonline</a>
Harper, D. (n.d.). Etymology of self-deception. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/self-deception