The idea of Bi Ritual clergy is something that troubles me.
David, my friend,
Periodically, that same comment crops up in EC circles and each time that it does I feel compelled to note that there were Byzantine parishes in this country (not so much of the Ruthenians or Ukrainians, as of the Melkites) that, for long periods, were served by biritual clergy - not infrequently assigned because they were available at the moment, rather than because they sought it out - who did their utmost to fulfill their responsibilities. Often, this was accomplished with little or no formal instruction. Parish histories from the era are replete with anecdotal remembrances, lovingly written, of these priests.
Did they sometimes fail to fulfill their sacerdotal responsibilities according to the letter of Byzantine praxis? Without a doubt. Did they sometimes, from ignorance or lack of knowledge, introduce latinizations or mix rubrics and ritual? Absolutely. Did they yet save parish communities from dissolution? Without a question.
I particularly remember the history of one parish whose long-serving biritual priest was thrilled when Archbishop Joseph, of blessed memory, was appointed Exarch and there was direction and leadership to the Church he had served for many years. Provided the opportunity to receive sound instruction in Byzantine praxis, he jumped at the chance and led his parish in delatinization and furnishing the temple according to traditional Byzantine norms. Reading the history, one could sense the emotion with which the writer spoke of him and the mourning into which the parish entered when he reposed.
May the memory of all those biritual clergy, who cared for our peoples when we lacked sufficient clergy of our own to do so, be eternal.
Is anybody as old as me ...
Bless, Father. Umm, the answer to the first half of that is a reluctant 'yes'. As memory serves, there's less than a year separating our length of tooth - and I forget which of us is longer in that regard (but I think it's you

).
... and remembers the days when bi-ritual priests were almost non-existent.
Yes, although I think that was more true elsewhere than in the US (the exceptions being the Society, particularly after the Russicum was founded, and the other religious orders that afforded clergy to serve in areas where persecution or a lack of seminaries made it difficult to sustain native clergy).
The Vatican saw it as a danger to the spiritual integrity and spiritual development of the priest to live in two worlds and two ethoses.
And, I would not disagree. Father Archimandrite Orestes (Karame), of blessed memory, told me of the strain he himself felt in serving the Melkite Church as a Jesuit. Albeit he loved the Society and considered that it had served his Church well, he ultimately felt compelled to request release from it to request incardination to the patriarchal clergy. I do think, however, that his task was more difficult because the Jesuits did not have a great presence in the Churches of the Middle East and that, I suspect, increased the sense of having a foot in each Church, but lacking full belonging to either.
In isolation from others of one's ilk - whichever one considers or wants that to be - it must be extraordinarily difficult to develop and maintain a fully centered spiritual focus. One hopes that the advent of modern communication, the ready availability of resources, and the resultant capability to develop and maintain community with one's fellow clergy, despite separation of time and distance, makes this a barrier more easily overcome than was once the case.
That thinking has obviously changed. Do we know when it changed and why? And has there been, as once feared, any negative effects on bi-ritual priests? Any studies done on this?
I think when and why probably would trace to the post-Vatican II era, when awareness of the very existence of Eastern and Oriental Christianity became less of a closely guarded ethnic secret (some good things came of that Council, despite the unintentional but more heralded unhappiness and discord for which it's most often cited). Personally, I am unaware of any notably negative effects on such priests, though it's a given that there have been some few instances in which some have taken on the mantle because it was 'a thing to do' - a quirky sort of fad. But, all of us, Catholic and Orthodox, have encountered that in converts or transferees and yet survived; the potential for it to negatively affect us is certainly greater in the case of clergy than laypersons who 'try us out' and seek to be 'more ___ , than the ______' but the number of clergy at whose door that charge can be laid is infinitely less, even proportionately, than the number of laity - so I don't think it is a lasting concern in that respect.
Without dredging through journals on the sociology of religion, I suspect it would be rather difficult to ascertain whether there have been meaningful studies done on the matter. That the question involves such a relatively minute slice of the clerical population doesn't preclude the possibility that someone, somewhere, has studied it - because, as we well know, social scientists like nothing more than to study some phenomenon that has escaped the notice of their peers - nothing like being the first on your block to raise a question and posit an answer - but I've not run across any such.
Many years,
Neil