Regarding the efficacy of sacraments administered outside the Catholic Church:
“The unity of the ecclesiastical body is so strong that only to those remaining in it are the sacraments of the Church of benefit for salvation” (
Council of Florence,
Cantate Domino, 1441: Denz. 714).
“A schismatic flatters himself falsely if he asserts that he, too, has been washed in the waters of regeneration. Indeed Augustine would reply to such a man: ‘The branch has the same form when it has been cut off from the vine; but of what profit for it is the form, if it does not live from the root?’” (
Pope Gregory XVI,
Mirari Vos, n. 13; 15 August 1832; cf. St. Augustine, in psalm. contra part. Donat. 21).
"‘He who deserts the Church will vainly believe that he is in the Church;’ ‘whoever eats of the lamb and is not a member of the Church, has profaned’ (
Ven. Pius IX,
Amantissimus, n. 3; quoting Ss. Cyprian and Jerome - 18 April 1862).
“From this it follows also that they cannot promise themselves any of the graces and fruits of the perpetual sacrifice and of the sacraments which, although they are sacrilegiously administered, are nonetheless valid and serve in some measure that form and appearance of piety which St. Paul mentions (I Cor. XIII: 3) and which St. Augustine speaks of at greater length: ‘The form of the branch,” says the latter with great precision, “may still be visible, even apart from the vine, but the invisible life of the root can be preserved only in union with the stock. That is why the corporal sacraments, which some keep and use outside the unity of Christ, can preserve the appearance of piety. But the invisible and spiritual virtue of true piety cannot abide there any more than feeling can remain in an amputated member’ (Serm. LXXI, in Matth., 32). But since they no longer have the sacraments, with the exception of baptism, which they confer, so it is said, without ceremonies on children; a fruitful baptism for the latter, provided that once the age of reason is reached they do not embrace the schism; but deadly for those who administer it, for in conferring it they willfully act in schism” (
Pope Leo XIII,
Eximia Nos lætitia, 19 July 1893).
“The Church… alone supplies those means of salvation which accord with the ordinary counsels of Providence” (
Pope Leo XIII,
Satis Cognitum, n. 9; 29 June 1896).
Ss. Cyprian, Jerome, Augustine, Leo I, Pelagius I and Thomas Aquinas (
ST, III, q. 82, a. 7) all wrote on the inefficacy of sacraments administered outside the Catholic Church.
The Holy Office stated that a Catholic may receive the sacraments from a non-Catholic (i.e. Orthodox) priest provided there was grave and urgent cause and that the priest administer the sacrament according to the Catholic rite without any mixing of the condemned rite (
Collectanea S. Congregationis de Propaganda Fidei seu Decreta Instructiones Rescripta pro Apostolicis Missionibus, Ex Typographia Polyglotta, Roma, 1907, vol. I, pp. 231, 692). Only then would the sacrament be licitly and thus efficaciously administered.
Unitatis Redintegratio appears to be in error when it states:
“The brethren divided from us also use many liturgical actions of the Christian religion. These most certainly can truly engender a life of grace in ways that vary according to the condition of each Church or Community. These liturgical actions must be regarded as capable of giving access to the community of salvation” (3.3).
UR appears to state that the sacraments of heretics and schismatics (besides baptism, which all admit) are efficacious.
Here is a thread on this very question:
groups.google.com/group/quaestionesdisputatae/browse_thread/thread/c2ed0dfecbf783f5