Regarding the logical fallacy, “Post hoc, ergo propter hoc” it needs to be noted that a cause
necessarily comes before an effect. Here is a definition (italics are mine):
Exposition:
The Post Hoc Fallacy is committed whenever one reasons to a causal
conclusion based
solely on the supposed cause preceding its “effect”. Of course, it is a
necessary condition of causation that the cause precede the effect, but it is not a
sufficient condition. Thus,
post hoc evidence may suggest the hypothesis of a causal relationship, which then requires further testing, but it is never sufficient evidence on its own.
fallacyfiles.org/posthocf.html
In regards to the liturgy and the decline in Mass attendance, we do have common sense,–the liturgy was radically altered,–fewer people went to the liturgy.
Also, as far as further “testing” that the definition above mentions, here is one article from “Homiletic and Pastoral Review” entitled,
Novus ordo Missae:
The record after thirty years
By Dr. James Lothian
Of course I can’t quote the whole thing, but here is a summarizing quote:
“The picture that emerges is distressing. Mass attendance of U.S. Catholics fell precipitously in the decade following the liturgical changes and has continued to decline ever since. This decline moreover is not an isolated phenomenon, confined solely to the Church in America. In England and Wales, the time pattern of Mass attendance has been just as bad, perhaps even worse. Church attendance of Protestants, in contrast, has followed a much different path. For most of the period it was without any discernible trend, either up or down. In recent years it actually has risen. The notion that the Catholic fall off was simply one part of a larger societal trend, therefore, receives absolutely no support in these data.”
catholic.net/rcc/Periodicals/Homiletic/2000-10/lothian.html
To not acknowledge the significant role the changes in the liturgy had with the decline is like a car manufacturer replacing a successful model with a brand new one which looks significantly different. Sales decline sharply (and yet not with all models). Do you think the manufacturer might actually think that his new model helped cause the decline in sales? That he’s not going to blame it all on societal trends?
Well, here’s hoping that Pope Benedict issues that Motu Proprio.