Outside the Church ...

...there is no Salvation

This dogma of the Catholic Church, sometimes abbreviated as EENS, appears to be misunderstood as much by Catholics as by non-Catholics.



Ludwig Ott, in Fundamentals of Catholic Dogma, states the dogma this way:

Membership of the Church is necessary for all men for salvation (De Fide)

I have witnessed a number of reactions to this dogma.

I've seen 'modern' Catholics recoil from the thought that all Protestants and Infidels (unbaptized) go to Hell.

I've seen others err in the opposite direction, insisting upon a mis-representation of this dogma.

As I've noted elsewhere, it is important to believe the truths of the Catholic Church as the Catholic Church does and not as we would wish them to be.

Summary of Church Teaching

• Everyone has an obligation to join the Catholic Church, the Mystical Body of Christ, and to remain united to Christ and His Vicar (the Pope).
• A person who knows that Catholic Church was divinely established by Christ, yet refuses to enter the Church or refuses obedience (note 1) to the Vicar of Christ cannot be saved.
• It is not necessary that a person be actually a member of the Church in order to be saved.  It is possible via a desire to belong to the Church, either explicitly or implicitly.
• Explicit desire would be manifest as a person being instructed in the truths of the Faith and dying before baptism.  The person had an explicit desire and it is possible that they obtained a state of sanctification.
• Implicit desire, when a person is in a state of invincible ignorance (note 2), and attempts to conform their will to that of God.
• In both cases the desire must be 'animated' with perfect Charity/Contrition (note 3) and have Super Natural Faith.
• The minimal requirement for obtaining supernatural faith is to believe that God exists and that He rewards those who seek him.(Heb. 11:6)

Where is the Church of Christ and Who is Inside?

In order to clear up any doubts, in Mystici Corporis (1943), Pius XII made it clear both where is the Church of Christ and who are actually its members.

If we would define and describe this true Church of Jesus Christ -- which is the One, Holy, Catholic, Apostolic Roman Church ^[12] -- we shall find nothing more noble, more sublime, or more divine than the expression "the Mystical Body of Jesus Christ" - an expression which springs from and is, as it were, the fair flowering of the repeated teaching of the Sacred Scriptures and the holy Fathers. (Mystici Corporis par13)

I'll note here that this definition of the Church raised the hackles of some theologians (neo-modernists?) in the Church at that time.  To the point that Pope Pius XII, reiterated this teaching in  Humani Generis.

With regards to who are inside the Church (ie. its members):

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." ^[17] 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. ^[18] And therefore if a man refuse to hear the Church let him be considered -- so the Lord commands -- as a heathen and a publican. ^[19] It follows that those 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. (Mystici Corporis par22)

This clearly outlines that the unbaptized, heretics (protestant), schismatics (formal and material) and excommunicates (certain degrees) are outside the Catholic Church, the Mystical Body of Christ.

Distinctions that Need to be Made

Heresy

Since formal heresy results in exclusion from the Mystical Body of Christ it is vital to understand how the Church assesses 'Heresy'.

Heresy is divided into four degrees, each of which has its own theological censure:

1. Heresy: Pertinacious adhesion to a doctrine contradictory to a point of faith clearly defined by the Church 
2. Approaching heresy: An opinion opposed to a doctrine that is not expressly 'defined' or clearly proposed as an article of faith by the ordinary/authorized teaching of the Church.
3. Erroneous in theology: A proposition that does not directly contradict a received dogma, but may logically lead to such a contradiction.
4. Suspected of heresy: An opinion whose contradiction of an article of faith is not able to be definitively proven, but can be reached with a certain degree of probability.

Material vs Formal Heresy

The Church notes that there are two types of heresy: Formal and Material.

A formal heretic is one who obstinately ('pertinaciously') holds a tenet that contradicts a point of faith. 

The Church has a stern warning for formal heretics:

Most firmly hold and in no way doubt that every heretic or schismatic is to have part with the Devil and his angels in the flames of eternal fire, unless before the end of his life he be incorporated with, and restored to the Catholic Church. (Catholic Encyclopedia)

A material heretic is one who is 'invincibly ignorant' of their error. In other words it is not their fault that they adhere to a heresy.

For material heretics the Church has the following teaching:

Towards material heretics her conduct is ruled by the saying of St. Augustine: "Those are by no means to be accounted heretics who do not defend their false and perverse opinions with pertinacious zeal (animositas), especially when their error is not the fruit of audacious presumption but has been communicated to them by seduced and lapsed parents, and when they are seeking the truth with cautious solicitude and ready to be corrected" (P.L., XXXIII, ep. xliii, 160).

Catholic vs Protestant Material Heretics

Catholic material heretics are not outside the Church because their error is deemed transient due to their willingness to submit to the Church (Art: Heresy).  However, the same cannot be said for Protestant material herestics as they obviously are not willing to submit to the Church's judgement on matters of faith and morals.

Material Schismatics

Material schismatics are in much the same situation as material heretics, with one major exception. In a number of cases they have access to all the sacraments. 

Because the sacraments provide grace ex opere operato, as long as the schismatic does not present any obstacles (ie is in a state of grace, and invincibly ignorant)  they will receive the grace of the sacrament. This places them, objectively speaking, in a better position to achieve a state of grace necessary for salvation.  

What is all the fuss about?

The reason is that while it is possible for those outside the Church to achive a state of grace and, if they die in that state, achieve eternal salvation, it does not appear probable.  A state of invincible ignorance concerning the Chruch does not confer a state of grace.

The real difficulty is our inability to read a person's soul and determine if they are in a state of invincible ignorance or not. This is what Pius IX had to say about the bounds of invincible ignorance:

Now, in truth, who would arrogate so much to himself as to mark the limits of such an ignorance, because of the nature and variety of peoples, regions, innate dispositions, and of so many other things? For, in truth, when released from these corporeal chains 'we shall see God as He is' (1 John 3.2), we shall understand perfectly by how close and beautiful a bond divine mercy and justice are united; but as long as we are on earth, weighed down by this mortal mass which blunts the soul, let us hold most firmly that, in accordance with Catholic teaching, there is "one God, one faith, one baptism" (Eph. 4.5); it is unlawful to proceed further in inquiry. (Pius IX - Wiki)

 Pope Pius XII in Mystici Corporis made this appeal to those outside the Church:

 As you know, Venerable Brethren, from the very beginning of Our Pontificate, We have committed to the protection and guidance of heaven those who do not belong to the visible Body of the Catholic Church, solemnly declaring that after the example of the Good Shepherd We desire nothing more ardently than that they may have life and have it more abundantly. Imploring the prayers of the whole Church We wish to repeat this solemn declaration in this Encyclical Letter in which We have proclaimed the praises of the "great and glorious Body of Christ," and from a heart overflowing with love We ask each and every one of them to correspond to the interior movements of grace, and to seek to withdraw from that state in which they cannot be sure of their salvation.  For even though by an unconscious desire and longing they have a certain relationship with the Mystical Body of the Redeemer, they still remain deprived of those many heavenly gifts and helps which can only be enjoyed in the Catholic Church. Therefore may they enter into Catholic unity and, joined with Us in the one, organic God of Jesus Christ, may they together with us run on to the one Head in the Society of glorious love. Persevering in prayer to the Spirit of love and truth, We wait for them with open and outstretched arms to come not to a stranger's house, but to their own, their father's home. (Pius XII, Mystici Corporis par103)

As Catholics we have to work with the with the objective truths that we can see. Protestants, Schismatics and Infidels are not members of the Catholic Church outside of which there is no salavtion.

Conclusion

So while it is possible for the unbaptized, Protestants and Schismatics to be saved despite not being actual members of the Church, their situation is dire and as Catholics we must strive to bring them into the Catholic Church.

Notes

1. Obedience: With regards to the canonically irregular situation of the SSPX:
1. However, not every disobedience is a schism; in order to possess this character it must include besides the transgression of the commands of superiors, denial of their Divine right to command. (Art: Schism)
2. Invincible Ignorance: 
1. The heretical tenets may be ignorance of the true creed, erroneous judgment, imperfect apprehension and comprehension of dogmas: in none of these does the will play an appreciable part, wherefore one of the necessary conditions of sinfulness--free choice--is wanting and such heresy is merely objective, or material. (Art: Heresy)
2. Ignorance is said to be invincible when a person is unable to rid himself of it notwithstanding the employment of moral diligence, that is, such as under the circumstances is, morally speaking, possible and obligatory. This manifestly includes the states of inadvertence, forgetfulness, etc. Such ignorance is obviously involuntary and therefore not imputable. On the other hand, ignorance is termed vincible if it can be dispelled by the use of "moral diligence". This certainly does not mean all possible effort; otherwise, as Ballerini naively says, we should have to have recourse to the pope in every instance. We may say, however, that the diligence requisite must be commensurate with the importance of the affair in hand, and with the capacity of the agent, in a word such as a really sensible and prudent person would use under the circumstances. (Art: Ignorance)
3. Perfect Act of Contrition: An act of contrition motivated by the love of God, with sorrow for having offended Him, and not tainted with imperfect contrition due to the fear of punishment.

References

LETTER OF THE SACRED CONGREGATION OF THE HOLY OFFICE to Archbishop Cushing - 1949
St. Thomas Summa III,Q68,Art2 Whether a man can be saved without baptism

MYSTICI CORPORIS CHRISTI, Pius XII -1943
Humani Generis, Pius XII - 1950
Catholic Encyclopedia Article - Heresy
Catholic Encyclopedia Article - Theological Censures
Catholic Encyclopedia Article - Religious Toleration
Catholic Encyclopedia Article - Ignorance
Catholic Encyclopedia Article - Schism
Fundamentals of Catholic Dogma, Ludwig Ott, 4ed 1960
Wikipedia: Extra_Ecclesiam_nulla_salus
The Three Errors of the Feeneyites