What has been presented is....
1) It's at least POSSIBLE that Mary had no other children. Irrelevant unless you document that it is biologically mandated the every act of sex results in a child.
2) Even a single act of loving sharing of intimacies within the Sacrament of Marriage means that the wife is less pure, less devoted to God, less committed. But nothing was shown to confirm this true or how it confirms that it is a dogmatic fact of highest importance to and for all and a matter of greatest certainty of truth that Mary Had No Sex EVER.
3. Ancient Catholic Tradition is to be rejected that embraces that the Incarnation and Annunciation happened on the same day, and that, while profoundly pressed, it is at least grammatically theoretically POSSIBLE that the present active tense COULD have some future implications so that while Mary said "I AM a virgin," this is MANDATED to mean "I will die - or not die - as a virgin and will have no sex EVER." But nothing has been shown that that's the grammatically mandated meaning, only that it's claimed that is a POSSIBLE meaning, if one rejects Catholic Tradition. (Nearly all the "apologetics" offered are attempts to say it's POSSIBLE - a point no one disputes and thus is irrelevant to anything).
4. Beginning around 220 AD, perhaps 180 years or so after Mary's death (the only one who could know if this tidbit of bedroom info is true), a church father said it was FALSE and denied it. This being the first reference to this view by "father" of the RC or EO denominations. Some years still later, a very controversal man often regarded as wrong embraced it as true although gave nothing to so indicate. As we move into the 4th and 5th centuries (HUNDREDS of years after the death of Mary), those who believed it seem to believe it. This proves that it is a dogmatic fact of highest importance to and for all and a matter of greatest certainty of Truth that Mary Had No Sex EVER.
You seem insistent on reversing our positions (I'm not sure why). Of all the denominations on the planet and in world history, there are only two that have an official position regarding Mary's sex life after Jesus was born (and in those two - it's a HUGE issue of ENORMOUS interest - it's proclaimed there in the boldest, loudest way possible that it is a dogmatic fact of highest importance for and to all and a matter of greatest certainty of truth that Mary Had No Sex EVER. No other says anything about how often She had sex (if at all) during her lifetime - just as they don't say how often you have sex. They are "silent as were the Apostles" (according to you). So, there are only two that have a position that must be substantiated - the RC and EO denominations. The proverbial "ball" is in YOUR court.
Your rubic of "It's a dogmatic fact of highest importance to and for all and a matter of greatest certainty of truth unless it can be proven false" is absurd and one YOU reject. Prove for us all that Joseph Smith didn't find those plates. Can't? Ah - then according to you, it's a dogmatic fact of highest importance to and for all and a matter of greatest certainty of truth that he did. Prove for us all that there are not 6.321 billion furry brown critters living on the Moon of Endor. Can't? Ah.... I'm actually certain you realize how absurd your rubric is - and yet you (and a few other members of the EO or RC denominations here) are defending and applying this very argument.
Consider...
The earliest source for this DOGMA of highest importance for and to all and greatest certainty of Truth that Mary Had No Sex EVER is not from Mary, Joseph, Jesus, any Apostle or anyone who even theoretically could have spoken to any of them. It's not from Scripture. It's not even from the earliest "Fathers" of the RC or EO denominations.
The earliest source typically noted for this Dogmatic fact of highest importance and greatest certainty that Mary Had No Sex EVER is the apocryphal Protogospel of James (circa 220), some 150 years perhaps after the death of Mary (the only one who could have known this tidbit of bedroom info). Oddly, it never mentions it. It does seem to express an opinion that Joseph was old (but not "too old to have sex") and that the noted siblings of Jesus were his - not Mary's. But it says nothing about Mary being a perpetual virgin or of Mary dying as a virgin. The author of this rejected book is unknown; there's no reason to theorize he was a "Church Father" in any denomination - then or now, nor is such commonly claimed.
About the same time, we have Tertullian (d, circa 220). However, he denied the virginity of Mary after Jesus' birth. He also firmly believed that the Jesus had brothers and sisters via Mary. This is the earliest personal witness we have to this issue, and he is a Church Father in both the RC and EO denominations.
Origen (d 254), by contrast, taught Mary's perpetual virginity. He is a controversal man - often at odds with official church teachings but he is the first one we know of that seems to affirm the teaching. He is generally regarded as a Church Father. He shares nothing to indicate that it's true, only that he believes it.
In the East, considerably later, St Basil the Great (d, circa 380) accepted Mary's perpetual virginity and claimed that it reflected the general sense of believers, though he did not consider it to be a dogma. This is at least 300 years after the death of Mary.
Among the sources for the above is the Catholic University of Dayton. campus.udayton.edu/mary/questions/faq/faq18.html
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