Scientific Consensus - How Consensus Can Change Over Time

How Consensus Can Change Over Time

See also: Theories and sociology of the history of science

There are many philosophical and historical theories as to how scientific consensus changes over time. Because the history of scientific change is extremely complicated, and because there is a tendency to project "winners" and "losers" onto the past in relation to our current scientific consensus, it is very difficult to come up with accurate and rigorous models for scientific change. This is made exceedingly difficult also in part because each of the various branches of science functions in somewhat different ways with different forms of evidence and experimental approaches.

Most models of scientific change rely on new data produced by scientific experiment. The philosopher Karl Popper proposed that since no amount of experiments could ever prove a scientific theory, but a single experiment could disprove one, all scientific progress should be based on a process of falsification, where experiments are designed with the hope of finding empirical data that the current theory could not account for, indicating its falseness and the requirement for a new theory.

Among the most influential challengers of this approach was the historian Thomas Kuhn, who argued instead that experimental data always provide some data which cannot fit completely into a theory, and that falsification alone did not result in scientific change or an undermining of scientific consensus. He proposed that scientific consensus worked in the form of "paradigms", which were interconnected theories and underlying assumptions about the nature of the theory itself which connected various researchers in a given field. Kuhn argued that only after the accumulation of many "significant" anomalies would scientific consensus enter a period of "crisis". At this point, new theories would be sought out, and eventually one paradigm would triumph over the old one — a cycle of paradigm shifts rather than a linear progression towards truth. Kuhn's model also emphasized more clearly the social and personal aspects of theory change, demonstrating through historical examples that scientific consensus was never truly a matter of pure logic or pure facts. However, these periods of 'normal' and 'crisis' science are not mutually exclusive. Research shows that these are different modes of practice, more than different historical periods.

Lastly, some more radical philosophers, such as Paul Feyerabend, have maintained that scientific consensus is purely idiosyncratic and maintains no relationship to any outside truth. These points of view, while provoking much discussion, have generally not caught on, even with philosophers.