From the Baltimore Catechism:

"The marriage of a Catholic before a minister or a civil official, such as a judge, a justice of the peace, a squire, or any clerk of court, is not really a marriage."

Regarding Catholics going inside any Protestant place of worship, from the 1962 Daily Missal:

"Those who go to places of worship belonging to other denominations, and knowingly do so in full agreement with, commit a mortal sin."

I have an acquaintance who is asking me (in his words)

Quote

 Do you know where it is written that Catholics should not attend the wedding of two baptized Catholics by a protestant pastor?

He attends a traditional chapel and he knows it is prohibited, he just needs a source.  Pardon my 'duh' factor today, but I'm not sure where to begin - there's so much information.  I suspect he is passing it on to others who need education on the subject too, so I want to provide the most succinct information possible.

Thank you for your time and assistance, dear friends.

It's not prohibited if one of those lapsed Catholics is family.

You just can't participate in such a sham "service".

Thank you all for your help.

MaterDominici, outstanding.  Just what I needed.

I scanned this previously from Fr. Jone's Moral Theology. You might find it useful.

Your post looks like it's from Hobbledehoy -- of course that's a good thing.
 

Quote from: MaterDominici

I scanned this previously from Fr. Jone's Moral Theology. You might find it useful.

Your post looks like it's from Hobbledehoy -- of course that's a good thing.
 

As our copy is already falling apart, I didn't have to destroy any books to scan this. : )

Canon 1258 1917 Code of Canon Law states: §1No one is allowed to believe in any way assist or actively take part in non-Catholic rites.

§2 Passive or merely material presence can be tolerated, the civil service or a mark of respect for the serious nature of the bishop in case of doubt prove the non-Catholic funerals, weddings and similar festivals, provided that the risk of scandal and perversion is absent.

Can 1258 §1. Haud licitum est fidelibus quovis modo active assistere seu partem habere in sacris acatholicorum.
 §2. Tolerari potest praesentia passiva seu mere materialis, civilis officii vel honoris causa, ob gravem rationem ab Episcopo in casu dubii probandam, in acatholicorum funeribus, nuptiis similibusque sollemniis, dummodo perversionis et scandali periculum absit.


Canon 2316  §1. Those who of their own accord, and the propagation of heresy in any way knowingly helps or who communicates with heretics in God contrary to the provision of can. 1258, is suspected of heresy.

Can 2316. Qui quoquo modo haeresis propagationem sponte et scienter iuvat, aut qui communicat in divinis cuм haereticis contra praescriptum can. 1258, suspectus de haeresi est.


The new code doesn't include this, BUT Mortalium Animos is still an infallible encyclical, and Pius XI explicitly forbids it.


http://www.vatican.va/holy_father/pius_xi/encyclicals/docuмents/hf_p-xi_enc_19280106_mortalium-animos_en.html

PS- Don't confuse active participation in non-Catholic services with attending the wedding of two baptized Catholics marrying outside of the Church, which is what the thread is asking. Those are to different subjects.

The non-Catholic marrying outside of the Church IS "actively participation in non-Catholic services", and thus is commiting a mortal sin for doing so, on top of the fornication he commits after the false "marriage".

The Catholic family members attending the sham, although they may not actually be actively participating, they are nevertheless contributing to the scandal, and are mortally sinning by (take your pick):

The Nine Ways of Being an Accesory to Another’s Sin

1. By counsel. 2. By command. 3. By consent. 4. By provocation. 5. By praise or flattery. 6. By concealment. 7. By partaking. 8. By silence. 9. By defense of the ill done.


The Seven Spiritual Works of Mercy

1. To admonish sinners. 2. To instruct the ignorant. 3. To counsel the doubtful. 4. To comfort the sorrowful. 5. To bear wrongs patiently. 6. To forgive all injuries. 7. To pray for the living and the dead.