Karl Popper’s theory of falsification contends that scientific inquiry should aim not to verify hypotheses but to rigorously test and identify conditions under which they are false.
Unlike verification, falsification focuses on categorically disproving theoretical predictions rather than confirming them.
Summary
Theory of Falsification
Karl Popper is prescriptive and describes what science should do (not how it actually behaves). Popper is a rationalist and contended that the central question in the philosophy of science was distinguishing science from non-science.
Karl Popper, in ‘The Logic of Scientific Discovery’ emerged as a major critic of inductivism, which he saw as an essentially old-fashioned strategy.
Popper replaced the classical observationalist-inductivist account of the scientific method with falsification (i.e., deductive logic) as the criterion for distinguishing scientific theory from non-science.
All inductive evidence is limited: we do not observe the universe at all times and in all places. We are not justified, therefore, in making a general rule from this observation of particulars.
According to Popper, scientific theory should make predictions that can be tested, and the theory should be rejected if these predictions are shown not to be correct.
He argued that science would best progress using deductive reasoning as its primary emphasis, known as critical rationalism.
Popper gives the following example:
Europeans, for thousands of years had observed millions of white swans. Using inductive evidence, we could come up with the theory that all swans are white.
However, exploration of Australasia introduced Europeans to black swans. Poppers’ point is this: no matter how many observations are made which confirm a theory, there is always the possibility that a future observation could refute it. Induction cannot yield certainty.
Popper proposed an alternative scientific method based on falsification. However, many confirming instances exist for a theory; it only takes one counter-observation to falsify it. Science progresses when a theory is shown to be wrong and a new theory is introduced that better explains the phenomena.
For Popper, the scientist should attempt to disprove his/her theory rather than attempt to prove it continually. Popper does think that science can help us progressively approach the truth, but we can never be certain that we have the final explanation.
Critical Evaluation
The great difficulty was that no run of favorable observational data, however long and unbroken, is logically sufficient to establish the truth of an unrestricted generalization.
Popper’s astute formulations of logical procedure helped to reign in the excessive use of inductive speculation upon inductive speculation, and also helped to strengthen the conceptual foundation for today’s peer review procedures.
However, the history of science gives little indication of having followed anything like a methodological falsificationist approach.
Indeed, and as many studies have shown, scientists of the past (and still today) tended to be reluctant to give up theories that we would have to call falsified in the methodological sense, and very often, it turned out that they were correct to do so (seen from our later perspective).
Also, one observation does not falsify a theory. The experiment may have been badly designed; data could be incorrect.
Quine states that a theory is not a single statement; it is a complex network (a collection of statements). You might falsify one statement (e.g., all swans are white) in the network, but this should not mean you should reject the whole complex theory.
Critics of Karl Popper, chieflyThomas Kuhn, Paul Feyerabend, and Imre Lakatos, rejected the idea that there exists a single method that applies to all science and could account for its progress.
References
Popperp, K. R. (1959).The logic of scientific discovery. University Press.
Further InformationThomas Kuhn – Paradigm ShiftIs Psychology a Science?Steps of the Scientific MethodPositivism in Sociology: Definition, Theory & ExamplesThe Scientific Revolutions of Thomas Kuhn: Paradigm Shifts Explained
Further Information
Olivia Guy-Evans, MSc
BSc (Hons) Psychology, MSc Psychology of Education
Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.
Saul McLeod, PhD
BSc (Hons) Psychology, MRes, PhD, University of Manchester
Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.
