Mass rules in extraodinary Circumstances

I know that there are very specific rules in canon law about the composition of the bread and wine used in mass as well as rules regarding the vessels etc.

I was wondering if there are also provision for waiving these rules. For example in a war zone, should a priest find himself without his mass kit, could he improvise in order to service those in his charge? How far could he go with his imporovisation?


No, because the rules touch on the very validity of the Sacrament itself. Just because Mass is being said in a war zone or such does not mean that something other than wheat bread or grape wine could be used.

Rather, the Church recognizes that Graces will flow to those who make Spiritual Communions in circumstances where Mass cannot be said due to lack of valid matter.

Yes there are still rules. For example, a Roman Rite priest may validly and licitly consecrate leavened bread, even bread with some mixture in it so as its still considered wheat bread (ie bakery store wheat bread). But he cannot use non-wheat bread.

Wine should still be pure grape wine. Depends on where you exactly are, it may still not be that difficult to procure grape wine. So blueberry wines.

Also the rules for the chalice and cup are also gone. So the priest may use a paper plate and paper cup if that is really all you have.

The rules on validity should cover all the circumstances. Beyond that the Eucharist is invalid no matter what. If you read RS, the definition of what can be consecrated is very loose compared to other documents dealing with ordinary circumstances. For example, while leavened bread is valid matter, it is very illicit and the celebrant is commiting a grave abuse should he use it in a normal Mass. But if there’s an earthquake or a war, the parish is destroyed, supplies are scarce, then the illicitness of leavened bread in the Roman Rite is lifted.

Thanks for the info. Most infomrative.

Forgive my ignorance, but what is “RS”?



Sorry but for what you have quoted is for ordinary use. What we are discussing is extreme cases, like if there was an earthquake or a war that would prevent the use of such items. Although you’re right that paper is absorbent and may retain some of the Precious Blood. Perhaps a plastic cup, or a ceramic or glass cup or mug.

Sorry, but I can find nothing stating that it would be otherwise even in extreme cases. Ans though war maybe a extreme case we have priest in war zones that celebrate the Mass without useing materials that are illicit.

There is no doubt but that everything is done to see that our priests are properly equiped with correct materials to say mass in out of the way places and in difficult situations.
I could never believe that there is not provision for extraodinary circumstances that would give a priest options outside of the norm. Afterall, God in His Church would never wish for his children to be without the Eucharist over some rules governing specific content etc. That would simply be Pharisitic.
Just as an even more “remote” example suppose a group, including a priest, is shipwrecked for a long period (years). Would they be completely unable receive the Eucharist? The Priest is required to say mass daily. How would that be handled?

I am interested, as I’m sure you are, in the sources for Constentine’s posts in this regard. He mentioned something about reading “RS” but failed to respond to my request for clarification. He must not have seen it.



In the case of Shipwrecked people if there is no priest then there is no mass. Also Preist are not required to say mass every day. They do I believe are requirement to say the LOTH everyday. I to would not wont to go without Mass and the Eucharist, but I would even more not want invalid matter used. Nor would I want the sacred vassels that do not reflect the honor of our Lord and may even bring desicration to the Eucharist. I have read through Redemptionis Sacramentum “RS” and can find nothing to support his claims.

There is a principle in law that says that “the law does not bind in an impossible situation.” Meaning that if it is impossible (truly impossible) for a priest to use licit vessels like a gold-plated chalice, then a priest is not bound by that law, and he may use whatever is best suited from what’s available. So, if there’s nothing else, a glass vessel can be used in place of a chalice. Likewise, a priest who finds himself in a situation where he has no vestments, he can still celebrate Mass; even though the law says that a priest must use proper vestments.

This is different though when it comes to what is valid (as opposed to what is licit). The bread and wine still have to be valid matter, no matter what the circumstances.

Thank you Father.
What would then constitute “valid matter” in the most extreme instance?


Thank you FrDavid.

Valid matter is the same no matter what. You can’t use blueberry wine and potato bread even in the event of a nuclear war and thats all you have in the bunker. What gets thrown out the window are only the requirements of licity. In normal times the bread should be only wheat and water. But if there is some mixture in the bread, it can still be valid as long as its still wheat bread. So if you have a bakery store wheat bread with some salt and sugar, it still is valid so as so it still considered wheat bread.

it must be wheat bread and grape wine.

Here’s what Redemptionis Sacramentum says about validity of matter for the Eucharist. This cannot be compromised no matter the situation:

  1. The Matter of the Most Holy Eucharist

[48.] The bread used in the celebration of the Most Holy Eucharistic Sacrifice must be unleavened, purely of wheat, and recently made so that there is no danger of decomposition.[123] It follows therefore that bread made from another substance, even if it is grain, or if it is mixed with another substance different from wheat to such an extent that it would not commonly be considered wheat bread, does not constitute valid matter for confecting the Sacrifice and the Eucharistic Sacrament.[124] It is a grave abuse to introduce other substances, such as fruit or sugar or honey, into the bread for confecting the Eucharist. Hosts should obviously be made by those who are not only distinguished by their integrity, but also skilled in making them and furnished with suitable tools.[125]

[49.] By reason of the sign, it is appropriate that at least some parts of the Eucharistic Bread coming from the fraction should be distributed to at least some of the faithful in Communion. “Small hosts are, however, in no way ruled out when the number of those receiving Holy Communion or other pastoral needs require it”,[126] and indeed small hosts requiring no further fraction ought customarily to be used for the most part.

[50.] The wine that is used in the most sacred celebration of the Eucharistic Sacrifice must be natural, from the fruit of the grape, pure and incorrupt, not mixed with other substances.[127] During the celebration itself, a small quantity of water is to be mixed with it. Great care should be taken so that the wine intended for the celebration of the Eucharist is well conserved and has not soured.[128] It is altogether forbidden to use wine of doubtful authenticity or provenance, for the Church requires certainty regarding the conditions necessary for the validity of the sacraments. Nor are other drinks of any kind to be admitted for any reason, as they do not constitute valid matter.

Well, yes and no. The difficulty is in throwing around phrases like “must” and “absolutely forbidden,” when it is unclear whether these refer to the conditions for validity or for liceity. So RS points out that the bread “must” be unleavened, yet leavened bread remains valid matter. It may be “absolutely forbidden” to use wine of doubtful provenance, yet the validity of the sacrament does not depend on the provenance of the wine but on whether it is pure wine made from grapes. Likewise the sacrament is valid even if no water has been mixed with the wine, or if the wine is unfermented and made from newly pressed grapes.

So it can be confusing merely to quote passages like this and say that it “cannot be compromised no matter the situation.” Leavened bread, for example, may be used in an appropriately dire situation, and would be valid matter in any situation.

I just love question as to just how far the line can be moved.

As mentioned earlier, the lines of validity cannot be moved. Only the lines of licity.

And in reallity we should not be moving either.

I wouldn’t say “in reality”. But under normal circumstances, which would be 97% of the time.

While most of us in the free world, extraordinary circumstance may mean “never”, however somewhere in the world today there are many Catholics who are under persecution. We have a guest priest who’s Canonically Chaldean, but he’s biritual so he celebrates Latin Rite Mass for us. He has many stories about persecution and war, like times where he has to ask people to stay home and not come to Mass for fear that they will be killed. A touching point of that story is that while he did say private Mass for that Sunday, a boy still showed up anyway despite the threat to their lives. But anyway, just to show that these extraordinary circumstances do happen today.

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