Alright so a couple preliminary things.  One, I don't actually know what subforum this should go in, its not exactly a Crisis in the Church issue (since its about objections brought up by EOs and thus not *directly* about indult vs R and R vs Sede, etc.) but I couldnt decide on a better option and I don't wanna just be one of those people who abuses the anonymous forum.  Second, I know some people will take this question the wrong way for various reasons, but I'd just prefer that people answer the question.  I'm aware that the objections I'm going to share here are wrong, I'm just looking to better *understand* *how* to articulate why they are wrong, etc.

Alright so I have a friend who converted from Protestantism to Eastern Orthodoxy around the same time I converted from Protestantism to Catholicism and recently he's brought up a few things that I'm trying to think through how to respond to.

The first is, while he admits that Mary is sinless, he denies the immaculate conception and that Mary was preserved from Original Sin because supposedly, according to him, all the Fathers taught that Mary had natural passions and suffered a natural death, which supposedly would only be possible if she contracted original sin.

Obviously we know the Immaculate Conception is dogma, but I'm wondering if the traditional *basis* for him being wrong is that somehow Mary having passions/a natural death can be *reconciled* with the IC, or if he's simply wrong about what he claims the Fathers held to.  Any patristic citations and arguments would definitely be helpful and appreciated here :) 

Second, this person argues that its inconsistent for Traditional Catholics (whether R and R or Sede doesn't matter so much here, though I realize both would have a somewhat different spin on this question, and I'd appreciate both perspectives for sure) to reject modernism/V2 on grounds that we think it contradicts Tradition, and yet condemn the EO for changing the creed in contrast with C'ple 879 which supposedly prevented even a Pope from doing this... going along with this would be a supposition that Popes did *not* believe they were above canon law in general in the 1st millennium.

I could fathom a few different ways of refuting this sort of thing, but I don't know which would be most accurate so I'm wondering what you guys think.

Thanks guys!

Good points, Stanley.  I would add that i've heard that Our Lady did undergo death because She wanted to follow Her Son's example and suffering.  But, Her body did not suffer any form of corruption/decay which is why it's called her "dormition/sleep" and not death.

The first is, while he admits that Mary is sinless, he denies the immaculate conception and that Mary was preserved from Original Sin because supposedly, according to him, all the Fathers taught that Mary had natural passions and suffered a natural death, which supposedly would only be possible if she contracted original sin.

Certainly Our Blessed Mother experienced passions, but without the inclination toward evil. This is because the taint of original sin never touched Our Lady.  As for her death, it is as Pax said, it is because Our Lord died that Our Lady died. And I agree with songbird, very sound advise.

Obviously we know the Immaculate Conception is dogma, but I'm wondering if the traditional *basis* for him being wrong is that somehow Mary having passions/a natural death can be *reconciled* with the IC, or if he's simply wrong about what he claims the Fathers held to.  Any patristic citations and arguments would definitely be helpful and appreciated here :)

I suggest studying Munificentissimus Deus (The Assumption) which gives details about the teachings of the Fathers regarding the death of Our Lady, and also Ineffabilis Deus (The Immaculate Conception) which also has the teachings of the Fathers as regards The Immaculate Conception.

Second, this person argues that its inconsistent for Traditional Catholics (whether R and R or Sede doesn't matter so much here, though I realize both would have a somewhat different spin on this question, and I'd appreciate both perspectives for sure) to reject modernism/V2 on grounds that we think it contradicts Tradition, and yet condemn the EO for changing the creed in contrast with C'ple 879 which supposedly prevented even a Pope from doing this... going along with this would be a supposition that Popes did *not* believe they were above canon law in general in the 1st millennium.

She doesn't, but, if the Church actually did teach that it's de fide that popes are always infallibly safe to follow, that the bishops teaching in unison with the pope are infallible, and that all councils are ipso facto infallible, then that means whether or not modernism/V2 contradicts tradition is altogether irrelevant, it also means that he is correct, that all trads are in grave error for denying or rejecting de fide teachings of the Church.

We know that although the masses believe they are, we know those are not teachings of the Church. It seems it should be easier to convince one who has not formerly learned such errors, what the truth of the matter actually is. For the most part, convincing anyone, even most trads that these ideas are not only not teachings of the Church, but are actually entirely false teachings can be a monumental task.        

So I got this from novusordowatch (https://novusordowatch.org/2017/01/thomas-aquinas-immaculate-conception/) but this PDF basically breaks down the immaculate conception issue. From what I can remember Mary did "contract" original sin (just like all humans) at conception but was preserved from it's stain (effects) by a special grace. So the body didn't corrupt the soul in the case of Mary.

What? From where do you remember this? Our Lady never contracted original sin, She is the Immaculate Conception.

“Concerning the most Blessed Virgin Mary, Mother of God, ancient indeed is that devotion of the faithful based on the belief that her soul, in the first instant of its creation and in the first instant of the soul’s infusion into the body, was, by a special grace and privilege of God, in view of the merits of Jesus Christ, her Son and the Redeemer of the human race, preserved free from all stain of original sin. And in this sense have the faithful ever solemnized and celebrated the Feast of the Conception.” -Ineffabilis Deus

Thomas Aquinas denied the Immaculate Conception.  He was wrong.



Here's why the pope added the filioque:



Eastern "Orthodoxy's" Fatal Flaw On Bishops & Ecuмenical Councils:



Eastern "Orthodoxy" Exposed: Their Heretical Doctrine Of God:



Mary's Sinlessness: A Biblical Docuмentary:



There might be other videos refuting EO on their channel.  You can browse or search for them.  They have a lot of material refuting Protestants too.

With the Photian schismatics I like to just point out how they agreed to the decrees of the Council of Florence which affirmed papal supremacy and the Filioque, the fact they were in Communion with us for 10 years (or that their sect ceased to exist for 10 years) meaning that they were in communion with heretics so according to their own standards they would have to say their sect defected from the true faith in the 15th century. I also point out the typical allowance of divorce and remarriage among them. A lot of the orthos you speak to about this really show their badwill when they quote fallible local synods to defend divorce and Matthew 19:9 despite the fact they allow divorce and remarriage for much more than porneia. When I pointed out that those synods were not infallible, this french ortho schismatic literally made it about universal jurisdiction. Sadly that french ortho in question has lead a whole novus ordo congregation in France including a priest into heresy and schism. I won't want to be him on judgement day, I'll tell you that.