The key difference between the heresy of quietism and the legitimate practice of hesychasm is that quietism involves a rejection of supplicatory prayer whereas hesychasm is an intense monastic system revolving around a very supplicatory prayer, the Jesus prayer.
And, more importantly, quietism forbids its practitioners from avoiding sin, on the grounds that once one has been perfected one must practice perfect passivity to God, even if that means sitting by while your body commits sin. See Monsignor Ronald Knox’s book
Enthusiasm.
The New Advent article, like most of what you will find on New Advent, is unfortunately not reliable. Their tendency to regard the spiritual patrimony of the Eastern Church as heretical was a common error at the time that the Church has since soundly rejected. Hesychasm is proclaimed to us Catholics as dogma by the restoration of the feast of St. Gregory Palamas on the Second Sunday of Great Lent as the completion of the Triumph of Holy Orthodoxy.
I think the article’s equation of quietism with pantheism is almost certainly incorrect. Rather, the quietists exaggerated the doctrine “I live, now not I, but Christ liveth in me”. Modern scholarship has given a much more sophisticated treatment of views of the relationship between God and created reality, rather than pinning a whole smorgasbord of views with the vague label “pantheism”. Christian dogma teaches us that we are deified by grace, that is, to quote the holy Elder Aimilianos Simonopetritis, “you must become God”, and this is not pantheistic in any sense.
Likewise, Thomist metaphysics, upheld as the standard frame of reference for theology in the West, teaches that God is
ipsum Esse - Being itself and absolute reality, while we are only real by participation (that is, God is our being though we are distinct from Him - to quote Meister Eckhart, “God exists us”, but as St. Thomas Aquinas pointed out, God is not the formal cause of our being, because we are distinct from Him). Hinduism has taken the conclusions of this truth to its logical consistency and declared that since God is Being therefore we are not absolute reality, that is we are illusion and God alone can be truly said to exist. I cannot honestly regard this as pantheism, because it emphasizes the transcendence of God (perhaps too much) rather than denying it. Gauging from the Catholic Encyclopedia article it seems the Quietists combined this stress on the transcendence of God with the dogma of divinization (a state it would seem they assume prematurely to have reached) to reach the conclusion that their existence is nothing other than God’s, they have been extinguished and exist only in God, and their actions are God’s. (This would be true if they were actually divinized - “Love God and do what you will”, to quote St. Augustine - but they err by supposing that the will is extinguished rather than divinized; that is, their view of divinization is not thorough.)
This is rather reminiscent of the Sufi spiritual doctrine, by which a saint’s existence is extinguished (
fana) only to continue to subsist in God (
baqa). A lot of ink is spilled over whether Sufism is an organic spiritual tradition that arose independently of any other one and happens to resemble other ones simply because truth is the same regardless of where it is discovered, or whether it was influenced by the Brahmanic Vedanta, Orthodox monasticism, or both. I am inclined to think all three - my point, however, is that this seems similar (and more thoroughly thought through) to the basic perception the Quietists were trying to grasp at, but more orthodox. (That Sufi mysticism is orthodox within the assumption of Christian revelation has been argued by a number of recent scholars, most notably the Melkite priest Fr. Louis Massignon in his four-volume monograph
Al Hallaj: The Mystic and Martyr of Islam, as well as the Catholic philosopher Edward Ingram Watkin.)
It is also open to question whether Fenelon actually held Quietist or semi-Quietist views. The afore-mentioned Edward Ingram Watkin, who flourished around the time of Chesterton, argued in his
Philosophy of Mysticism that Fenelon was defending the genuineness of Madame Guyon’s mystical experience, without actually agreeing with her errors (mystics after all have fallible intellects, and fallible interpretations of their experiences - and are often aware of this fact, as one can tell by reading the
Divine Revelations of Blessed Juliana of Norwich).
All in all, I agree with Azurestone’s statement that Quietism is like perverted hesychasm, and I would add to that that it was a degraded version of the practice of the presence of God.
**