Celibacy is tied to the very nature of the priesthood, even as Christ united celibacy to the priesthood in his own person. It is a discipline which could change, but it would be horrible if it did change.
The real history of "married priests" is that the common practice in the early Church was for married men to cease living as husbands with their wives at the time of their ordination. Furthermore, even today, when a married man is ordained (for example, when a married man is ordained a permanent deacon), he makes something like a "conditional promise" of celibacy, since he is not permitted to remarry after ordination if his wife dies. Holy Orders tends towards celibacy.
We consider the joy and the fruitfulness of priestly celibacy as we look at the life of the Leper Priest of Molokai, St Damien.
“Missionary priest, born at Tremeloo, Belgium, 3 January
1840; died at Molokai, Hawaii, 15 April 1889. He was sent to the mission of the
Hawaiian Islands, where he arrived, 19 March, 1864. Ordained priest at Honolulu
24 May of the same year. On 10 May, 1873, Father Damien, at his own request and
with the sanction of his bishop, arrived at the settlement [on Molokai] as its
resident priest. There were then 600 lepers. He not only administered the
consolations of religion, but also rendered them such little medical service
and bodily comforts as were within his power. He dressed their ulcers, helped
them erect their cottages, and went so far as to dig their graves and make their
coffins. After twelve years of this heroic service he discovered in himself the
first symptoms of the disease. On 28 March, 1889, Father Damien became helpless
and passed away shortly after, closing his fifteenth year in the service of the
lepers.” (From the Catholic Encyclopedia)
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