In an interview with Vatican News about Pope Francis’s apostolic exhortation Amoris laetitia, Vatican Secretary of State Cardinal Pietro Parolin suggested that it represented a “paradigm change” for the Catholic Church. George Weigel promptly countered: “The Catholic Church Doesn’t Do ‘Paradigm Shifts’” (First Things, Jan. 31, 2018). Rightly noting the origin of the concept of “paradigm change” in Thomas Kuhn’s classic The Structure of Scientific Revolutions, Weigel went on to characterize a paradigm change as “a dramatic, sudden, and unexpected break in human understanding—and thus something of a new beginning.” He cited the established principle that revelation “ended with the death of the last apostle.” There may be “development” of doctrine but only in continuity with “the faith once...delivered to the saints.” Such development would be an elaboration of the original paradigm, not the replacement of one paradigm with another.
Cardinal Parolin offered no account of Pope Francis’s presumed paradigm change beyond a “change of attitude,” “a new spirit…of approach.” Weigel suggested that Parolin may mean only that we should treat those who deviate from church doctrine “with sensitivity and charity.” That, wrote Weigel, would be “a worthy proposal” but hardly a “paradigm shift.”
To understand this issue it is necessary to explain the special character of a paradigm change. Kuhn distinguishes change in “ordinary” science from a “revolutionary” paradigm change. There is constant change in ordinary science as new observations are made and the scope of a theory is expanded. Revolutionary paradigm change occurs when a new theory shifts the fundamental framework that controls the data. The shift from Newton to Einstein is a classic example.
In Newtonian physics, space, time, and matter are unchanging and independent of one another: matter exists in absolute space and time. Motion is relative to the fixed measures of space and time. When space, time, and matter are fixed, material objects can accelerate by the simple addition of velocities. A bullet fired from a speeding train hits its target with the velocity of the shot plus the speed of the train.
Newton’s model broke down in the late nineteenth century when the speed of light was found to contradict it. Whether one was moving toward or away from an approaching light ray, the speed of light was constant. There were various attempts to solve the problem in order to make the new observations fit Newton’s assumptions. Someone even tried to explain the observations by suggesting that the impact of light rays shortened the measuring rods.
Einstein accepted that the speed of light was constant and challenged the assumption that space, time, and matter were fixed. He proposed that space, time, and matter were “relative” to the position of the observer. Roughly speaking, in Einstein’s theory, space and time become space-time and matter becomes a wrinkle in space-time. For Newton, matter remains the same regardless of acceleration; in relativity theory, mass increases with acceleration, reaching theoretical infinite mass as the object approaches the speed of light.
Kuhn argued that a paradigm change was “revolutionary,” but is such a change really as disjunctive as Weigel suggests? The theories of Ptolemy, Copernicus, Newton, and Einstein represent paradigm changes, but they are, after all, developments within the same science of cosmology. Every cosmology necessarily deals with the same range of subjects: space, time, matter, and motion. Nor does a paradigm change simply abandon the truths of the previous theory. Einsteinian cosmology includes the Newtonian equations for local systems while demonstrating their inadequacy on the vast scale unveiled by modern astronomical observation. It is in a way unfortunate that Einstein’s theory came to be labeled “relativity,” suggesting, as it might to some, that the laws of physics were now up to the observer. Not at all. Einstein’s theory was based on a fixed constant—the speed of light—and offered transformation equations that allowed observers to agree despite being on different observation platforms.
In short, a paradigm change can retain significant continuity with past theory even as it changes the fundamental framework. If Parolin’s comment is correct, some shift of a fundamental framework would have to occur in our understanding of the church. What would that look like?