Scientific Revolutions

Kuhn's model of scientific evolution emphasizes alternating periods of ‘normal science’ and revolutionary transformations. In this context, ‘normal science’ refers to the routine work of scientists who focus on solving specific “puzzles” within their field. Kuhn posits that this problem-solving is the primary activity in which scientists engage throughout their careers.

During normal science, scientists dedicate their efforts to resolving particular issues, contributing to a perceived continuity of progress.

Although normal science appears to advance steadily, Kuhn challenges the realist notion that scientific theories are directly linked to truth. He argues that during revolutionary phases, scientific development does not follow a linear path but rather entails a significant re-evaluation and alteration of established scientific beliefs and practices.

The framework within which scientists evaluate truth is embedded in a ‘lexicon’—a specialized linguistic corpus that derives meaning from the prevailing paradigm. Kuhn elaborates on this idea through the concept of a ‘disciplinary matrix,’ which encompasses the shared theories, methodologies, and values that underpin scientific research.

A paradigm is anchored by a core theory and supported by auxiliary hypotheses. While the core theory remains stable, auxiliary hypotheses are adjusted as new contradictory data emerges. Eventually, as the conflicting data accumulates, the primary theory may be abandoned or radically transformed, marking the onset of a revolutionary phase.

Kuhn suggests that following a radical paradigm shift, the new paradigm and its corresponding phase of normal science often stand in stark contrast to the previous one. This leads us to consider the concept of ‘incommensurable paradigms.’

Incommensurable Paradigms

Kuhn defines ‘incommensurable’ as the lack of shared semantic or methodological ground between competing paradigms, making it impossible to conduct meaningful comparisons or determine progress between them. To address this challenge, Kuhn introduces five criteria for evaluating theories: accuracy, consistency, scope, simplicity, and fruitfulness.

While these criteria provide a rational basis for assessing theories within and across paradigms, they are not without limitations. The subjective nature of their application often leads to divergent interpretations among scientists, creating a tension between shared values and individual perspectives.

The first limitation arises from the inherent subjectivity in applying Kuhn’s criteria, as scientists may interpret and prioritize these values differently. The second and third limitations extend from this subjectivity, as the ambiguous nature of the criteria complicates the ability to make direct comparisons between theories.

Kuhn acknowledges that the variability in how these criteria are understood and applied leads to persistent incommensurability, particularly in his later works.

Concluding Remarks

The key takeaway from these limitations is that the interplay between Kuhn’s criteria can lead to conflicts—such as prioritizing simplicity over accuracy or vice versa—while the subjective interpretations of these values undermine their effectiveness as a definitive guide for theory evaluation.

Consequently, Kuhn’s framework appears insufficient for establishing a clear method for determining the best scientific theories within specific paradigms. If this is accurate, then rationality may play a minimal role in guiding theory choice under Kuhn's characterization.

Despite these challenges, Kuhn’s insights into scientific development remain both unique and thought-provoking. The question of whether scientific revolutions or “paradigm shifts” occur is still open to debate, but Kuhn’s ideas compel us to reconsider the true nature of scientific inquiry and progress.

The first video offers an engaging overview of the Scientific Revolution, exploring its historical significance and impact on modern science.

The second video compares the Scientific Revolution with the Enlightenment, highlighting key differences and connections between these transformative periods in history.