The legacy of Kuhn’s idea of scientific revolutions

1. The legacy of Kuhn’s idea of scientific revolutions “No neutral algorithm for theory choice, no systematic decision procedure which properly applied must lead each individual in the group to the same decision” Postscript, The Structure of Scientific Revolutions, 2nd edition, p. 200

2. Main points in today’s discussion: • Kuhn’s considered opinion in later works • Legacy of Kuhn’s challenge to the ‘received’ view: further developments of Kuhn’s concepts of ‘Theory-ladenness of observations’ and ‘incommensurability’

3. Epistemic Relativism • Ladyman’s account: “a particular theory in physics or biology might be counted as knowledge just because it is believed by those with influence and status within the community of physicists or biologists” (116). • General view: A claim is held to be true because an individual, or a group of individuals, believe it is so.

4. Epistemic Relativism • Consider the argument for epistemic relativism: • Group a believes X • Group b believes ~ X • Therefore, there is no objective way to tell whether or not X is true; it is a matter of opinion • This argument is invalid because the conclusion does not follow from the premises. It doesn’t follow that there is no objective way to find out whether or not X is true.

5. Epistemic Relativism • Another argument against relativism: the self-reference argument • Is the claim that truth is relative to a paradigm itself objectively true? • If the answer is ‘yes’, what can we infer? • There is one paradigm-independent truth • If the answer is ‘no’, what can we infer? • This is their opponent’s position.

6. The later Kuhn • In his later works, Kuhn sought to distance himself from the relativistic interpretation of the concepts of theory-ladenness and incommensurability. • He argues that the aim of his analyses is not to say that science is an irrational enterprise, but rather to offer a historically accurate account of the workings of science

7. The later Kuhn • Kuhn writes: “Good reasons for choice provide motivations for conversion and a climate in which it is more likely to occur. … [But] good reason [does not] constitute conversion, and it is that process we must explicate in order to understand an essential sort of scientific change” (Postscript to The Structure of Scientific Revolutions, 2nd ed., 204)

8. The later Kuhn • The position that the later Kuhn supports is that there is “no neutral algorithm for theory choice, no systematic decision procedure which properly applied must lead each individual in the group to the same decision” (Postscript to The Structure of Scientific Revolutions, 2nd ed, p. 200)

9. The later Kuhn • What is an algorithm? • Algorithm: “step by step procedure for solving a problem” (Merriam Webster’s Collegiate Dictionary) • The ‘received’ view in philosophy of science thought of ‘scientific method’ as providing a set of rules for theory choice. • Is this an accurate description of Popper’s program of falsification?

10. The later Kuhn • If Kuhn is right, and there is NO algorithm for theory choice, it appears that we are left with the following conclusion: • Either theory choice is irrational or the view that scientific method is like a strict set of rules is untenable. • Kuhn’s position is the view that scientific method provide a strict set of rules is untenable. To make sense of scientific practice, we need to adopt a non-algorithmic view of scientific method

11. Core scientific values (p. 121) • To further distance his work from the claim of irrationality, Kuhn argues that there are five core scientific values: • A theory should be empirically accurate within its domain • A theory should be consistent with other accepted theories • A theory should be wide in scope and not just accommodate the facts it was designed to explain • A theory should be as simple as possible • A theory should be fruitful in the sense of providing a framework for ongoing research

12. Core scientific values • These values place constraints on what scientists should do in terms of developing theories • However note that these values are not sufficient in themselves to constitute an algorithm for theory choice. Why? • Values may be interpreted differently. What is ‘simple’? • Values may conflict, or there may be trade-offs: for example, less simplicity for more fruitfulness

13. Impact of Kuhn’s analysis • With the five core values, Kuhn argues that science is a rational enterprise; it isn’t ‘anything goes’ • The later Kuhn still challenges the received view: • Science is still not cumulative • The appeal to the context of justification in the received view is problematic because the context of justification is not ‘universal’—can be read off independent of context—since all judgments are made from within a paradigm

14. Kuhn’s legacy: social constructivism • If Kuhn’s view of paradigm dependence of beliefs are right, the existence of objects are also paradigm dependent. ‘Electrons’ exist in the electron-paradigm, but they do not in another. • This leads to social constructivism. The view that entities in some domain exist but they do not exist over and above our construction of them in the paradigm

15. Social constructivism • An extreme form of social constructivism is the claim that our understanding of the world is determined by the language we use. • This is known as the Sapir-Whorf hypothesis named after anthropologists Edward Sapir and Benjamin Whorf

16. Social Constructivism • Whorf: "We dissect nature along lines laid down by our native languages. The categories and types that we isolate from the world of phenomena we do not find there because they stare every observer in the face; on the contrary, the world is presented in a kaleidoscopic flux of impressions which has to be organized by our minds—and this means largely by the linguistic systems in our minds. ... [All] observers are not led by the same physical evidence to the same picture of the universe, unless their linguistic backgrounds are similar, or can in some way be calibrated." (from Language, Thought and Reality pp. 212–214).

17. Kuhn’s legacy: sociology of knowledge • Another way in which Kuhn’s idea can be made even more radical is taken up by sociologists of science, for example the Strong Programme in Sociology of Knowledge. • Whereas Kuhn took the history of science seriously, the Strong Programme argues that science should be studied ‘scientifically’ • What does study science ‘scientifically’ mean?

18. Sociology of Science • Since scientists look for causal connections in their investigations, science should also be examined in terms of causes. • This means that researchers should be looking at the causes of our beliefs. • The symmetry principle: ‘seek the same causes for scientific beliefs, true or false’

19. Sociology of knowledge • This is a serious challenge because we typically offer different explanations for truths and for falsehoods. • How do we explain falsehoods? Truths? • What is the implication of the claim that truths are caused by social factors? • What makes truths true? • What would the ‘received’ view say about the symmetry principle?