On Miracles Outside the Catholic Church

What Is At Stake: No Salvation Outside the Catholic Church
(1) No adult who dies without being received into the Catholic Church or explicitly desiring to be received into the Catholic Church can be saved [Denzinger 247, 423, 430, 468-469, 570b, 714].
(2) God can give natural enlightenment (e.g., by a missionary) or supernatural enlightenment (e.g., illumination) to people who through fault of their own are ignorant of the Catholic Church (e.g, they are in a remote forest and cannot find out about the only true Church through study) who sincerely seek truth and do the will of God to the best of their ability by following the dictates of their conscience so that they do not perish without first being received into the Church or explicitly desiring to be received into the Church; "if someone [who] is brought up in the forest or among wild beasts ... followed the direction of natural reason in seeking good and avoiding evil, we must most certainly hold that God would either reveal to him through internal inspiration what had to be believed, or would send some preacher of the faith to him as He sent Peter to Cornelius (Acts 10:20)" [St. Thomas Aquinas, The Disputed Questions on Truth, Vol. II , Q. 14, a. 2; trans. Robert W. Mulligan, S.J. (Eugene, OR: Wipf & Stock, 1952, 262)" and"God may enlighten, at the hour of death, one who is not yet a Catholic, so that he may see the truth of the Catholic faith, be truly sorry for his sins, and sincerely desire to die a good Catholic" [Fr. Michael Müller, Familiar Explanation of Christian Doctrine; cf. Denzinger 1647-1648, 1677-1678].

No True Miracles Justify Schism from Catholic Church
1. The reports of posthumous miracles worked by lifetime loud formal schismatics (of whom there is no documentation of entrance into or desire for entrance into the Catholic Church before they died),{1} which have not been verified by anything close to such a trustworthy body as the meticulous Congregation for the Causes of Saints, are a priori extremely unlikely. According to the 2003 New Catholic Encyclopedia 9:669-670, while God sometimes works miracles outside of the Catholic Church to manifest His presence in certain events, support a doctrine that separated Churches have retained from the Catholic Church, or to increase the faith of individuals, He never works miracles in circumstances that could, with good reason, be construed as confirming a non-Catholic "religion as a whole or ... a doctrine" opposed to the teachings of the Catholic Church. Any so-called miracles of this sort are the product of (1) demons; (2) imagination; (3) hallucination; (4) exaggeration; (5) legendary accretion; or (6) outright fabrication.{2}

Causes of Occurrence of Some Miracles Outside Catholic Church
2. There are certain Eastern Orthodox individuals (material and not formal schismatics and heretics){3} who work miracles, within the limits described above. Cf. Monden, in his masterful work cited below, 135-136.

On Incorrupt Relics
3. My Wonderworkers blog has many pictures of purportedly supernaturally incorrupt Christians. According to p. 306 of the Jesuit Fr. Louis Monden's Signs and Wonders, "pre-canonization inquests in the Orthodox Church are very different from their Roman counterparts. Examination of the bodily remains is of primary importance; perfect preservation is a favorable and often conclusive factor warranting canonization. ... the norms applied in these inquests concerning miraculous events are not the same as the strict rules applied by the Catholic Church, and thus no purported miraculous facts may be accepted as such without prudent critical investigation in every case." The Russian Orthodox Church censured Evgeni Evstigneevich Golubinski when he said that incorruptibility is not an essential mark of sanctity, according to p. 457 of the Assumptionist Fr. Martin Jugie's Le Schisme Byzantin.

4. Don't assign too much weight to incorruptibility. It is not a be-all end-all indicator of sanctity, there are different degrees of incorruptibility (e.g., John Maximovitch of Shanghai and San Francisco [†1966] is brown and withered, whereas St. Charles of Sezze [†1670] has full, lifelike flesh and normal coloration), and rigorous investigation is required to determine whether the causes are supernatural in individual cases. How is it that, for instance, men like St. Alphonsus Maria Liguori (an example of a loyal son of the Catholic Church, obedient to the Holy See as is required for salvation for everyone who is not invincibly ignorant) and the "incorrupt" Athanasius of Brest could both be members of the Church? Can a formal schismatic be a saint, with alleged incorruptibility manifesting that he was right to persist in notorious formal schism until the end of his life?

Apologetic Value of Catholic Miracles
5. There have been many true miracles in support of dogmas and doctrines that the Orthodox have (but not via an ecumenical council) forsaken: e.g., Eucharistic miracles with unleavened as opposed to leavened bread,{4} God endorsing the theology of St. Thomas Aquinas,{5} and the Θεοτόκος proclaiming her Immaculate Conception to St. Bernadette Soubirous.{6} Moreover, "major prodigies" with intrinsic apologetic value are absent outside of the Catholic Church, according to Fr. Monden, whose meticulous study of the issue is a must-read. Fr. Monden says there are no miracles which lack "Christian salvific signification," and that we have to dismiss a priori "any miracle sought or 'obtained' to confirm heresy tor to buttress an heterodox creed," or any so-called miracle "which, whether or not directly sought or obtained to confirm error, would by its context suggest or confirm such an interpretation."{7} Cf.

Notes & References
{1} E.g., Alexis Toth (ex-Catholic), Athanasius of Brest, John of Kronstadt, Mark of Ephesus, etc. See the documentation of their hostility to the Catholic Church at http://thebananarepublican.blogspot.com/2010/02/extra-ecclesiam-nulla-salus-part-2.html.
{2} The Catholic Church has the Congregation for the Causes of Saints to rule out cases that belong to one or more of those categories. Historically, the Catholic Church has been much more rigorous than the Orthodox Church in this regard. Jugie, Martin, A.A. Le Schisme Byzantin: Aperçu historique et doctrinal. Paris: P. Lethielleux, 1941, p. 450.
{3} Cf. Ecumenical Council of Vatican II, Decree on Ecumenism Unitatis Redintegratio 3.
{4} On the Eastern Orthodox absolute rejection of the use of unleavened bread, see the following: Two Epistles of Patriarch Michael I Cerularius of Constantinople to Patriarch Peter III of Antioch; Encyclical of Metropolitan Mark Eugenikos of Ephesus (1440); Council of Constantinople with Patriarchs Jeremiah II Tranus of Constantinople, Silvester of Alexandria, and Sophronius IV of Jerusalem (1583); Encyclical of the Eastern Patriarchs Anthimus VI of Constantinople, Hierotheus II of Alexandria, Methodius of Antioch, and Cyril II of Jerusalem to Bl. Pope Pius IX of Rome (1848); Encyclical of Patriarch Anthimus VII of Constantinople to Pope Leo XIII of Rome (1895).
{5} Kennedy, Daniel. "St. Thomas Aquinas." The Catholic Encyclopedia. Vol. 14. New York: Robert Appleton Company, 1912. 21 Sept. 2009 <http://www.newadvent.org/cathen/14663b.htm>.
{6} "Biography of Bernadette Soubirous." Biography Online. 2 Oct. 2009 <http://www.biographyonline.net/spiritual/bernadette-soubirious.html>.
{7} Fr. Louis Monden, S.J., Signs and Wonders: A Study of the Miraculous Element in Religion (New York: Desclee Company, Inc., 1966), Chapter 7, Section I: "The Possibility of Authentic Miracles Outside the True Church," 135-136. Cf. St. Thomas Aquinas (Angelic Doctor), Summa Theologica II-II, q. 178, art. 2, ad 3.