Having researched the history of psychic phenomena in general and psionics specifically, I have learned a few interesting things that I would like to share as background and history... which I will try to recall off the top of my head, as I'm away from my notes.
One: the history of mental abilities that are specifically not magic go back thousands of years in human history. Especially in the mythology of India. Therefore, magic and psi / psychic stuff are not the same thing, psi / psychic powers are not another version of magic, and they never have been the same. Having said that, magical effects that duplicate the mental powers I am referring to, and blending of the line between magical and mental have also been a thing, both in history and especially in more recent times, which leads to a lot of modern confusion of the two.
WotC using the same mechanics for both didn't help, despite making it easy for newcomers to pick up.
Two: the term "psionics" was invented and coined by a certain pulp novel writer who combined "psi" and "electronics" and used it to mean "electronics that used units of mental energy to function". Incidentally, said units of mental energy were called "psions (plural), and psion (singular)".
Sorry WotC, you didn't invent it, and you're not even using it correctly. (Assuming that the original definitions have primacy and precedence. )
Beings who could use psions of mental energy to produce effects or power psionic equipment were usually called "heroes / heroines / villains / aliens / etc., with Psi abilities", sometimes Espers, especially later on. This swiftly became popular, and a wide spread acceptance of the terminology soon embedded itself into fantasy, and more especially into space opera and science fiction. Eventually, the term psionics came to replace the term Psi as the more common usage.
Three: the term Psychic was more associated with the communication with the spirits of the dead, seances (especially in the early to mid 1900s), certain magical traditions such as the Chaldean, the Babylonian, or the Witch of Endor... and again with people who cheat and deceive others for money, power, and influence. It is only in modern times that the term psychic has been diluted and used to mean all Psi phenomena and powers in general. The term psychic has also been largely overshadowed by the term psionics.
Four: the term bionics actually comes from the term psionics, not the other way around, in the sense that it is electronics that interface with biology. Though it is rare to see actual devices that are powered by biology in the original sense of the word, as opposed to cybernetics. The Dark Sun lifeshaped grafts would count as wetware, rather than bionics. Should units of biological energy be called bions then? I think perhaps the term Bio-E became more prevalent thanks to TMNT.
Five: the resurgence of interest in psychic phenomena in the 1900's coincided roughly with an increasing trend rejecting the pseudo-mystical and mystical traditions of magic / majik / magick / etc., (and occasionally mystical-religious) trappings so often donned by the many deceivers looking to take financial, political, religious, mental, and social advantage of susceptible people.
Six: there were many documented cases of mental phenomena in the 1800s and 1900s (research titanic references for just a few of the many) that people were trying to reason about and understand, and the idea of psi phenomena resonated with those who rejected the magical or mystical and sought a more scientific explanation for such. Ironically, many modern scientists reject one of the very things that contributed its part to the advances of scientific research of the era.
Seven: the 50s, 60s, and 70s contributed their bit to openmindedness and the rejection of the rat race, which had various influences on how Psi and Psychic phenomena was viewed, perceived, and accepted (or rejected).
It was this accumulated history that the creator of the original psionic rules in Supplement III: Eldritch Wizardry drew upon in 1976. Those rules, and the powers therein, have heavily influenced the concepts of Psi, the Psychic, and psionics ever since.
In the original edition, "psionic abilities" function like discrete abilities.
In 1st edition, more definitions (and rules) were given, and three powers were added.
When 2nd edition came out, psionics had been removed, as Gygax had indicated he would do in a Dragon Magazine article; even though 2nd ed was published after he was booted from the company.
Later in 2nd ed, the "psionic world" Dark Sun was released, where "magic was hated and feared, while psionics were accepted in daily life"... and ironically (or maliciously) did not contain any rules for psionics - you had to buy a second book, the Compete Psionic Handbook in order to get the Dark Sun psionic system. This is notably the first time the Attack Modes and Defense Modes were converted to powers (not in 3.5 as many believe).
Containing references to both Greyhawk and Forgotten Realms, it officially if backhandedly applied psionics to both 2e worlds in addition to the world of Athas.
Two more books with psionics were released for 2nd ed Dark Sun: Dragon Kings, and The Will and the Way (which introduced epic level psionics for the first time to D&D, called High Sciences, as well as revising the 2e psionics system).
As the Dark Line was not continued into 3rd edition, WotC declared that Athas.org was the official sponsored source of all 3rd edition Dark Sun content, all of which would be co-owned with WotC, an unprecedented legal status unique to all the Other Worlds sites hosting discontinued lines, which has never been officially rescinded, and is mostly, if not completely, ignored these days.
