In a July 30, 2025 article titled The Data Is In! Vatican II Devastated the Church, author Chris Jackson sets out to demonstrate, through statistical data, a direct causal relationship between the Second Vatican Council and the collapse of Catholic life. The text summarizes and compares two main analyses. The first is a 2025 study by economists Robert Barro, Edgard Dewitte, and Laurence Iannaccone, titled Looking Backward: Long-Term Religious Service Attendance in 66 Countries. This study, applying an event-study method, concludes that the Council "triggered" a global decline in Mass attendance—a uniquely Catholic phenomenon, not correlated with a general trend of secularization. The second analysis comes from the 2003 work of Kenneth C. Jones, The Index of Leading Catholic Indicators, which compiles Church statistics in the United States, contrasting the robust growth of 1960 with a collapse in all measurable categories (priests, seminarians, religious sisters, Mass attendance) by 2002. Jackson concludes that such data refutes the common objection that this would be a post hoc ergo propter hoc fallacy, asserting that the causality is empirically verified.
The compilation of statistical data showing a decline in religious practice after the Second Vatican Council is not, to an attentive observer, a revelation, but rather the quantification of a disaster already acknowledged—though intermittently—even by the Supreme Pontiff himself (Amerio, p. 6). The accumulation of numbers regarding the decline in the number of priests, the abandonment of religious life, or the decrease in sacramental participation serves to give measurable contours to a crisis that, in essence, is not numerical but principled. Statistics are the visible effect; the cause lies in a change of substance.
The value of such studies lies in their ability to refute the spurious optimism that attempts to present the post-conciliar period as a “new springtime” or to deny the very existence of the crisis, attributing the phenomena of decay to a vague "spirit of the age" or to secular trends that would have affected the Church regardless (Amerio, p. 2, 7). The data presented by Barro, Dewitte, and Iannaccone are significant precisely because they isolate the phenomenon: the Catholic decline does not mirror that of other denominations, but begins uniquely and sharply precisely after 1965. This confirms that the crisis is internal, born of self-demolition, and not primarily the result of external assault (Amerio, p. 6).
However, the analysis cannot stop at mere temporal correlation, even if causally established. The numbers are a symptom. The 90% reduction in seminarians in the United States, mentioned by Jones, is not an isolated phenomenon, but the result of a crisis in the priesthood, where the very concept of priesthood was altered, bringing it closer to the common priesthood of the faithful and emptying it of its ontological specificity (Amerio, p. 145, 152). The drastic drop in the number of religious sisters corresponds to an analogous crisis in religious orders, where the principles of stability, obedience, and the very purpose of consecrated life (the salvation of one's own soul) were replaced by a horizontal and worldly orientation (Amerio, p. 261, 263).
The decline in Mass attendance from 75% to 25% directly reflects the loss of unity in worship (Amerio, p. 566). The liturgical reform, with the abolition of Latin and the introduction of the principle of creativity, transformed sacred, objective, theocentric action into subjective, psychological, and anthropocentric action (Amerio, p. 485, 500). When 70% of young Catholics deny the Real Presence, as Jones points out, this is not an abstract catechetical failure, but the logical consequence of a Eucharistic theology that diluted the dogma of transubstantiation, favoring notions of transignification or mere spiritual presence in the assembly (Amerio, p. 471). The same Institutio Generalis of the new Missal, in its original Article 7, contained a definition of the Mass that deviated notably from the doctrine of Sacrifice, as has been widely demonstrated (Amerio, p. 479).
The staggering increase in marriage annulments, from 338 to 50,000, is the juridical manifestation of the crisis in matrimony, where indissolubility—once defended as a natural and divine law—gave way to a new conjugal spirituality that prioritizes “community of life and love” over the procreative end and objective bond (Amerio, p. 517, 519).
Therefore, statistics are not the cause, nor is the Council as an isolated historical event the primary cause. The cause is the underlying change in the principles that inform the faith and life of the Church. Numbers do not lie, but they also do not explain everything. They merely measure the distance from a previous state. The true analysis consists in identifying the alteration of principles that made such a decline possible. The crisis is not that the numbers have fallen; the crisis is that the doctrines that sustained those numbers were altered, making the fall an inevitable consequence. The value of such studies is to confirm that the change in principles did not lead to renewal, as was expected, but to widespread ruin.
References
AMERIO, Romano. Iota Unum: A Study of Changes in the Catholic Church in the 20th Century. Revised version. September 2011.
JACKSON, Chris. The Data Is In! Vatican II Devastated the Church. Hiraeth In Exile, July 30, 2025.
