Three Worlds – MC Escher (1955)
This “authenticity,” also tackled by Derrida, inspired by Aristotle and Heidegger, is a central preoccupation. Is it possible to stay in this state always? If so, how?
[..] I have been strongly impressed by the radical opposition between everyday life-which is lived in semiconsciousness and in which we are guided by automatisms and habits without being aware of our existence in the world-and of the privileged states in which we live intensely and are aware of our being in the world. Bergson as well as Heidegger clearly distinguished these two levels of the self: the self that remains at the level of what Heidegger calls the “they,” and the one that rises to the level of what he calls the “authentic.”
Pierre Hadot
The Present Alone is Our Happiness
Time's Flow Stemmed 
Have to read Hadot!
Yes, Sigrun, I couldn’t recommend him more highly.
Authenticity is neither a state nor a level: states and levels are indeed temporary, and notoriously precarious. Authenticity is merely what remains when inauthenticity has fallen away.
That’s why all pursuit of authenticity is counterproductive, a truism that has nothing to do with Buddhism except in the sense that early esoteric Buddhist (along with esoteric Judaic, esoteric Christian, Hindu Advaita, Sufi, etc.) texts articulate it: If one is pursuing “authenticity” — reading about it, thinking about what others have written, gaining inspiration from others’ accounts, trying to absorb and adopt the presumed perspectives and perhaps even the behavior of mentors, gurus, teachers, philosophers — such pursuit is in and of itself grossly inauthentic, to the extent that it may forever foreclose the possibility of exit, except in utter defeat. (Same with “peace of mind”: any attempts to secure or perpetuate it inevitably are movements away from equilibrium.)
The permanent dissolution of inauthenticity (aka “self,” and no, there cannot be two selves) is certainly possible, but without total abandonment of one’s environment and habits — in short, one’s “life” — it’s extremely difficult and in no way can be self-induced. (Alzheimer’s, stroke, brain damage, and/or brain tumors of course may facilitate or provoke it, but….)
Hence, the desert, the hermitage, the forest, Vanaprastha, Sannyasa, Xiao Yao You….
Yes, “state” is a poor word choice. I think, “level,” as Hadot uses the word is better. “Value” may have served, as I think of “authenticity” as an ethical value.
I’m not convinced that merely reading and thinking about authenticity is “grossly inauthentic.” A lot depends on how you define “authenticity,” which is subjective (the thinkers are deeply ambivalent about defining authenticity), possibly even beyond the limits of language. But I agree you cannot ape others’ behaviour in the quest for authenticity. There is inspiration and examples to be found, but no prescriptions. Each attempt to become what one truly is is personal, and yes, could easily end in “utter defeat”. But perhaps what is significant is the search, even if to quote Heidegger we fail “proximally and for the most part.” The desire to live genuinely and resist the depersonalisation and objectification of modern society is worthwhile in itself.
I suspect that the answer doesn’t lie in hermitic existence, much as I’d love to find a reason to spend my life wandering wide-eyed in the desert. As highly social animals, authenticity is more likely to be found in a social and community context. If I take inspiration from the main thinkers on authenticity, they are all clear on this point, even, uncharacteristically, Kierkegaard.
OK. Given those qualifications, then, I’d reply “absolutely not” to your question of whether it’s possible to remain permanently in the state or at the level of authenticity that Hadot’s describes, because any desires or attempts to “live genuinely” are themselves products of conditioning, external influence, social stimulus, ego gratification, etc. The “authentic” is a radical negative, a profound absence of qualities, not the result of a conscientious search or sincere efforts at self-betterment.
It seems significant to me that when philosophers and writers (from Kierkegaard and Nietzsche to Sartre, Camus, and beyond) try to portray “authentic” persons, they inevitably resort to fictional or mythological (anti-)heroes because they can’t come up with any real humans who’ve “risen” to the level of the “authentic.” I don’t think this means there aren’t any, but simply that by virtue of their authenticity, it’s not likely such people come to our attention, and even less likely that we identify them as “authentic” if they do.
It also seems significant to me that all of our philosophical and cultural notions about “authenticity” come to us from people who admittedly or obviously lack it. This isn’t a criticism of them (no doubt >99% of all humans lack it), but it indicates the status of “authenticity” as a concept, a commodity, a product, not unlike yoga or zen or the latest so-and-so diet.
Yes, all the prototypes are fictional, even the various representations of Socrates, who arguably came closest.
I’ve come to the same conclusion that living authentically as a permanent state is undesirable and not possible, but the striving is, on some level, worthwhile.