"Half in and half out" are your words.  What the Church teaches is that a person can be united to the Church perfectly or imperfectly, and the Body/Soul terminology has been used for centuries as a means of explaining it.  Here is how Bellarmine does so:  


Bellarmine says a person can be united to the Soul but not the Body (in re), yet possess the state of grace (charity), which is precisely what you said "is not Catholic."  And what Bellarmine wrote about can be found all throughout the pre-Vatican II theology manuals.

You are quoting St. Robert, but he is not the Church, so to say the Church teaches that one may belong to one or the other, or one but not the other is pure speculation from, in this case, St. Robert, not the Church. And finding it all throughout pre V2  theology manuals is only purely speculative ideas from theologians, and again, not from the Church.
 
Meanwhile, the actual Church's teaching does teach the thrice defined dogma that there is no salvation outside of the Catholic Church (soul and body, which are inseparable). The reason that it is impossible to in any way attain salvation without being inside the Church, is because that is contrary to the dogma.

Anytime you read the error that that there are adults who are not in the Catholic Church through no fault of their own, you are reading error, you are reading that which is contrary to the doctrine of the Divine Providence, no matter who says it or where it comes from. The error on top of that error is that one may belong to the soul of the Church and not even know it, and the body in voto.

I have two questions: What is required to be saved?  And what does it mean to be within the Catholic Church?

Mystici Corporis Christi:

“Actually, only those are to be included as members of the Church who have been baptized and profess the true faith, and who have not been so unfortunate as to separate themselves from the unity of the Body, or been excluded by legitimate authority for grave faults committed. ‘For in one spirit’ says the Apostle, ‘were we all baptized into one Body, whether Jews or Gentiles, whether bond or free.’ As therefore in the true Christian community there is only one Body, one Spirit, one Lord, and one Baptism, so there can be only one faith. And therefore, if a man refuse to hear the Church, let him be considered – so the Lord commands – as a heathen and a publican. It follows that those who are divided in faith or government cannot be living in the unity of such a Body, nor can they be living the life of its one Divine Spirit.”

Dr Ludwig Ott explains:

“According to [the encyclical letter Mystici Corporis Christi] three conditions are required for membership of the Church: a) The valid reception of the Sacrament of Baptism. b) The profession of the true Faith. c) Participation in the Communion of the Church. By the fulfilment of these three conditions one subjects oneself to the threefold office of the Church, the sacerdotal office (Baptism), the teaching office (Confession of Faith), and the pastoral office (obedience to Church authority).”

Mgr Van Noort explains further:

“The unity of faith which Christ decreed without qualification consists in this, that everyone accepts the doctrines presented for belief by the Church’s teaching office. In fact our Lord requires nothing other than the acceptance by all of the preaching of the apostolic college, a body which is to continue forever; or, what amounts to the same thing, of the pronouncements of the Church’s teaching office, which He Himself set up as the rule of faith. And the essential unity of faith definitely requires that everyone hold each and every doctrine clearly and distinctly presented for belief by the Church’s teaching office; and that everyone hold these truths explicitly or at least implicitly, i.e., by acknowledging the authority of the Church which teaches them.”

Pope Leo XIII, in his encyclical letter Satis Cognitum, authoritatively expounded on this:

“Agreement and union of minds is the necessary foundation of this perfect concord amongst men, from which concurrence of wills and similarity of action are the natural results. Wherefore, in His divine wisdom, He ordained in His Church unity of faith; a virtue which is the first of those bonds which unite man to God, and whence we receive the name of the faithful – ‘one Lord, one faith, one baptism’ (Eph 4: 5). That is, as there is one Lord and one baptism, so should all Christians, without exception, have but one faith. And so the Apostle St. Paul not merely begs, but entreats and implores Christians to be all of the same mind, and to avoid difference of opinions: ‘I beseech you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no schisms amongst you, and that you be perfect in the same mind and in the same judgment’ (I Cor 1:10). Such passages certainly need no interpreter; they speak clearly enough for themselves. Besides, all who profess Christianity allow that there can be but one faith. It is of the greatest importance and indeed of absolute necessity, as to which many are deceived, that the nature and character of this unity should be recognized. And, as We have already stated, this is not to be ascertained by conjecture, but by the certain knowledge of what was done; that is by seeking for and ascertaining what kind of unity in faith has been commanded by Jesus Christ.”

Pope Benedict XII, Benedictus Deus, 1336, ex cathedra: “By this Constitution, which will remain valid for perpetuity, We define with apostolic authority that, according to the universal ordering of God, [i.] the souls of all holy men who departed from this world before the Passion of our Lord Jesus Christ, [ii.] as also those of the holy Apostles, martyrs, confessors, virgins and other faithful who died following their reception of the sacred baptism of Christ, in whom nothing was to be purged when they departed, nor should be when they depart in the future, or if there was at that time, or should be, anything to be purged in the same, then, when they shall have been purged after their death, [iii.] and the souls of children reborn in that same baptism of Christ and of those to be baptized when they shall have been baptized, dying before the use of their free will, immediately after their death and the aforesaid purgation of those who stood in need of a purgation of this kind, even before the resumption of their bodies and the General Judgment, following the Ascension of our Lord and Savior Jesus Christ into Heaven, have been, are, and will be in Heaven, in the Kingdom of Heaven and in the Celestial Paradise with Christ…”

Lastly Pope Boniface VIII Unam Sanctam:

Furthermore, we declare, we proclaim, we define that it is absolutely necessary for salvation that every human creature be subject to the Roman Pontiff.

But sedevacantists are not united in government.  And according to Pius XII if they are not united in government they cannot be living in the unity of the body, nor can they be living the life of its one Divine Spirit.  How, then, can a sedevacantist be saved?


If being subject to the Roman Pontiff is "absolutely necessary for salvation," how can a sedevacantist be saved?  And in case you didn't notice, the dogma makes no exception for those who die during an interregnum.  

To use Stubborn's reasoning, since this dogma is infallibly true, it must necessarily follow that Divine Providence will ensure that all those who are to be saved (the predestined) do not die during an interregnum.  

Amazing, you twist the meaning just like a Liberal RT. The sedes add "unless you do not believe the pope is the pope" to the end of the dogma, that's how they think they get around or out of it. For those who are not members of the Church, they cannot be saved since they do not even know of this requirement for salvation.

Lastly Pope Boniface VIII Unam Sanctam:

Furthermore, we declare, we proclaim, we define that it is absolutely necessary for salvation that every human creature be subject to the Roman Pontiff.

Right, and we add to this that the Council of Trent defined that only those who have received the Sacrament of Baptism are subject to the Roman Pontiff, to the exclusion of catechumens.

One of the toughest hurdles for BoD theology is the EENS definition that states there is no salvation outside the Church "of the faithful", fidelium.  Msgr. Fenton acknowledges that this technical theological term, fideles, excludes Catechumens.  He tries to save BoD by asserting that people can be within the Church of the faithful without actually being one of the faithful ... a huge stretch.

Neither were the Catholics during the Great Western schism MATERIALLY united in government, but only formally by professing subjection in principle to a Roman Pontiff.  Some theologians have speculated that the See may have been vacant the entire time.  Per Trent, all the Baptized are subject to the Roman Pontiff, and they must also profess adherence to the Pontiff to formally retain that subjection which is required for salvation.  This element can remain whether or not there happens to be an actual Roman Pontiff on the See at any given moment in history.

For all your arguing that Vatican II teaches no error, Vatican II in fact says that those who are not in subjection to the Roman Pontiff materially, such as Protestants, are still within the Church of Christ due to lack of culpability for the original sin of schism.  So Vatican II openly rejects your assertion.

Well put.

The interregnum objection put forth by RT and the straw men of Stubborn are pilpul red herrings designed to distract from the larger issues at hand.