In Catholicism since when did willfully violating Sunday Mass obligation become mortal sin? In the history of the Catholic Church, what led to the classification of willfully violating Sunday Mass obligation to be mortal sin?  I'm looking for the origin of canon law, council document, encyclical, etc.  Approximate date and the "who" is important for the answer.  Better yet, the historical circumstances and the reasoning leading to that classification.

Sunday Mass obligation is obviously derived from one of the Ten Commandments: keep the Sabbath day holy.  My question is instead about the Catholic Church formalization / institutionalization of the obligation with the attendant penalty of mortal sin.
Scriptural basis
Exodus 20:8:

Remember that thou keep holy the sabbath day.

cf. Kellner's Heortology § 2. Sunday and its Observance as a Day of Rest (pp. 6-13)
Holy Office's March 4, 1679, condemned proposition 52
DZ 1202:


The precept of keeping feast days is not obligatory under pain of mortal sin, aside from scandal, if contempt be absent.


Hearing Mass on Sundays is a precept of the Church.
One of the precepts of the Church is &quot;To hear Mass on Sundays and holydays of obligation.&quot; This was codified in the the 1917 Code of Canon Law can. 1247:

§1. Feast days of obligation for the universal Church are: All Sundays […]

and can. 1248:

Mass must be heard on feastdays of obligation […]Festis de præcepto diebus Missa audienda est […]

Canonist Dom Augustine writes (commentating on 1917 can. 1248):

This obligation obliges all the faithful of the Latin Church and the inhabitants of China and other missionary countries under the S. C. P. F. [Sacred Congregation de Propaganda Fide]5

[…] S. C. P. F. Sept. 12, 1645 (Coll., nn. 126, 189, 114).

The obligation is grievous, binding under mortal sin. One does not comply with this precept by hearing two or even four parts of Masses said simultaneously by different priests.6

S. O., propp. 52, 53 damn., March 4, 1679 […]



Pope Pius VI condemned the errors of the 1786 Synod of Pistoia in his August 28, 1794, constitution Auctorem fidei #74 (DZ 1574). The false council did not even dare abrogating the precept to hear Mass on Sundays.


The deliberation of the synod about transferring to Sunday feasts distributed through the year […] abrogating the precept of hearing Mass on those days, on which according to the early law of the Church, even then that precept flourished; […] a false proposition, harmful to the law of the general Council and of the Supreme Pontiffs, scandalous, favorable to schism.