Well, this idea came from a conversation with Alex Olar back in April. Holy Saturday it was, I think. As Catholics we celebrate Sunday as the Lord’s day of course. But, however, what if we could take Saturday as a day of rest as well and double the “liturgical weekend”? I can’t remember exactly what Alex was saying that led to this, but the IIT team and I decided to investigate so here we are with our conclusions to our study, formatted in the way of St. Thomas Aquinas.

Whether Saturday be also the Sabbath?

Obj. 1: According to Aristotle, time in the sense of specificity is a category of being, but among his ten highest predicables it is only an accident, not a substance itself. Thus the question of an accidental notion of day, is pointless, Saturday cannot be the Sabbath any more than Sunday or any other day, and the question of applying a denomination to an arbitrary day of the week is pointless as a substance is not an accident and vice-versa.

Obj. 2: As Eusebius says, “the Sabbath had been transferred to Sunday”. Now transfer etymologically implies a generation and corruption change whereby the old no longer is while a new has come to be. Therefore, the Sabbath is now Sunday alone, the old definition of it as being Saturday corrupted and no longer in any state of being.

Obj. 3: Furthermore, as Christ says, “The Sabbath was made for man, not man for the sabbath; so the Son of Man is lord even of the Sabbath.” Now as God made the Sabbath, it would be contrary to his nature for him to change his will once set. Thus, the Sabbath, as a creation of God “made for man” must necessarily be unchanging and so occur in reference to time on the day known as Saturday, and that alone, as Sabbath is used a singular here.

On the contrary: A day can be so in two ways, both according to calendar, and according to liturgy and sometimes these definitions are incorrectly used as the same in account.

I answer that: Saturday and Sunday are both the Sabbath. This is evident by a geometrical argument of equivalency of magnitudes, a geometrical argument of similar angles in similar figures, an argument of fulfillment and fittingness in reference to the human and divine natures of Christ, a practical argument of the whole being greater than the part, an argument from the temporal characteristics of the Old Sabbath and an argument from the modern practicality of time zones.

If the days of the week are considered as equal magnitudes, as they are, the ratio of Saturday to the week, as it is equal to a day, must be equivalent to the ratio of a day to the week. The same follows for Sunday. Thus as Saturday and Sunday share the same ratio to the week and are equal to each other (Book V: Proposition 9). Things which are equal to each other cannot be contraries. Thus Sunday identified now as being defined as the sabbath, cannot be the contrary of a Saturday supposed to be a non-Sabbath. Thus, the conclusion follows.

In speaking of “day” one must consider its etymological use in Latin as the word “dies”. Now, dies is a fifth declension noun where the singular and plural nominatives of the word are identical in spelling. When speaking of the word day then, there is much potential for confusion of whether one is considering it in the singular or in the plural sense. This equivocal definition allows in many cases the use of “day” and “days” interchangeably when the word’s meaning is taken as a subject. Thus, the Sabbath as a day in the old law can be used when one thinks in the official language of the church, Latin as also a subject of days, under which both Saturday and Sunday are possibilities for consideration.

The whole must be greater than the part argues Euclid as a common notion known to all. Now as the Faith of the Church comes as a fulfillment of what is lacking in the Old Law, it must necessarily be somehow greater than the Old. What is greater must be larger, and to be properly grasped in its truths by the finite, the time spent in study of the being that it is must also be greater. Now, either part of the Old Law Sabbath was a “waste of time” an absurdity, or more time is now required for the exercise of the Faith, time that must be greater than a single day, as that greater than a day: must be greater than a day. Therefore, at least two calendar days must be appropriated in the New Law to that which was the Sabbath in the Old.

Also, 2 Peter 3:8 says: “Don’t forget this fact, dear friends: With the Lord a single day is like a thousand years, and a thousand years are like a single day” it seems that a “single day” must be a changeable accident present in some higher substance. As such, there is no 

If it were not, then by the law of non-contradiction, Saturday must either be the Sabbath or be not, and Sunday must be the Sabbath or be not. There is no allowance for the Sabbath to be both

The being of one instant in time can admit at the same time of different accidental notions of time. For example, while it may be 10pm in New York on Saturday, it may be 3am in London on Sunday. But it is in some sense still a moment in being singularly while admitting of two definitions with respect to viewpoint and subjectivity with reference to objective differences in the category of space. Thus, saying it to be the Sabbath on Saturday in no way opposes Sunday also in speech to be the same.

As there are several ways in which a day can come to be per se we must recognize that the word day is equivocally stated and be prepared to accept its proper usage in several respects. We know that six days are seen as the maximum for work, not the minimum, as from the original declaration of the Ten Commandments, “You have six days in which to do your work” (GT)  Nothing is said, however, about doing work on fewer days than these, as in the case of a two day sabbath. Since we are not breaking God’s command by interpreting both Saturday and Sunday as the Sabbath by our justified argument we must then accept it as fact by the syllogistic product of our deductions.

Reply to Objection 1: Although time as one of the ten categories is an accident, the objection itself admitted to the being of a time in which notions of specificity are accidental to this higher nature. Therefore, as in Genesis 1, God established the times and seasons within the being of his creation, one could consider days such as Saturday and Sunday to exist within the natural order as part of the nature of the larger Time itself. Furthermore, as God specifically created day and the same word of “created” is applied to the formative work of God to other beings, some other sense of the word time must be implied in the use here of this concept. For as it is represented by signs, and as Augustine argues that signs stand for things, time must itself be here a thing and the question has a meaning.

Reply to Objection 2: Transference in the modern Theological sense within the Roman Catholic Church primarily means transferring the celebration of a feast day which occurs on some day to the nearest Sunday as a means for reducing the number of times Catholic must attend Mass. In this sense, Eusebius’s use of the word transference only implies that what by nature is celebrated on Saturday is celebrated contrary to nature as an application to Sunday, replacing the true Sunday celebration.  He does not speak of some transferrance of nature and according to being so the being of Sabbath can still be truly said to be in both days as a few choose accidentally to refer to the day on different calendar days.

Reply to Objection 3:  The Sabbath is not to be recognized as an unchangeable thing by this very same verse. When Christ says the “Son of Man is lord even of the Sabbath” he shows how he has power to change an interpretation improperly applied in the past to one twenty-four hour period for the idea of the sabbath to a more inclusive and broader one. As Lord and God he can most definitely do this for the betterment of man in the changing situations in which His creatures live without violating his unchanging nature as God. It is here not God that changes, but the will of God, unchanging that is received properly in different ways by men in different circumstances to differing ends.