Paradigm shift

A paradigm shift is a fundamental transformation in the basic concepts, experimental practices, and theoretical assumptions of a scientific discipline. The term was introduced by Thomas Kuhn in The Structure of Scientific Revolutions (1962) to describe discontinuous transitions in scientific development — moments when the accumulated anomalies of normal science overwhelm the dominant framework and precipitate a crisis resolved only by the adoption of a new paradigm.

Paradigm shifts are not merely changes in theory; they are changes in what counts as a valid problem, a valid method, and a valid solution. Before the Copernican revolution, the question 'why do the planets move?' was answered by reference to natural place and celestial perfection. Afterward, it was answered by gravitational mechanics. The question remained, but the ontology within which it made sense had been entirely replaced. This is why Kuhn described rival paradigms as incommensurable — they cannot be evaluated by shared standards because they do not share standards.

From a systems perspective, paradigm shifts are regime changes in the network topology of scientific belief. A paradigm is not a single hypothesis but a densely interconnected web of concepts, methods, and instrumental practices. Shifting paradigms requires not merely replacing one node but rewiring the entire network — which explains why paradigm shifts are so rare, so contested, and so traumatic for the communities that undergo them. The resistance to paradigm shift is not mere conservatism; it is the structural inertia of a complex belief system that cannot be partially destabilized without risking total collapse.