Science versus Pseudo-science: The problem of demarcation

1. Science versus Pseudo-science:The problem of demarcation Alireza Monajemi, MD-PhD Philosophy of Science Department, Institute for Humanities and Cultural Studies

2. The importance of the problem

3. What is science?

4. The straightforward answer

5. we are asking what common features all the things on that list share? = • what it is that makes something a science?

6. The problem of demarcation

7. Science is just the attempt to understand, explain, and predict the world we live in • Although these are the features of science, but in this sense astrology are also included

8. Philosophy of science on the problem of demarcation

10. Vienna circle • The distinguishing features of science lie in the particular methods scientists use to investigate the world. • One of the key problems in philosophy of science is to understand how techniques such as experimentation, observation, and theory- construction have enabled scientists to unravel so many of nature's secrets.

11. Vienna circle • Meaningfulness (tautology v.s empirical) • Verification • Sense data

12. Fact, hypothesis and theories

13. Theory • Theory is a conceptual framework that explains existing observations and predicts new ones. • It can incorporate facts, laws, inferences, and tested hypotheses

14. Hypothesis • : A tentative statement about the natural world leading to deductions that can be tested. • If the deductions are verified, the hypothesis is provisionally corroborated. • If the deductions are incorrect, the original hypothesis is proved false and must be abandoned or modified.

15. Fact • In science, an observation that has been repeatedly confirmed and for all practical purposes is accepted as “true.” • Truth in science, however, is never final and what is accepted as a fact today may be modified or even discarded tomorrow.

16. Popper • Two major criticisms of Vienna circle’s criterion of demarcation: • The problem of induction (Russell story) • Exclusion of scientific theories

17. Popper’s criterion of demarcation • Falsifiability • ‘It will rain or not rain here tomorrow’ will not • be regarded as empirical, simply because it cannot be refuted; • whereas • the statement, ‘It will rain here tomorrow’ will be regarded as empirical.

18. Popper’s criterion of demarcation • Theories are, therefore, never empirically verifiable. • System as empirical or scientific only if it is capable of being tested by experience. These considerations suggest that not the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation.

19. Popper’s criterion of demarcation • it must be possible for an empirical scientific system to be refuted by experiment.

22. Popper versus Vienna circle • Vienna circle • Meaningfulness • Empiric • Verifiability • Exclusion of theories • Popper • Meaningfulness • Empiric • Falsifiability • Inclusion of theories

23. Lakatos criticism of Popper • Science is not some propositions but science includes some research programs. • Cross sectional studies is not enough to show that a research program is scientific or not.

24. Lakatos criterion for demarcation • ]Progressive scientific theories are those which have their novel facts confirmed • and • degenerate scientific theories are those whose predictions of novel facts are refuted.

25. Lakatos criterion for demarcation • a theory is pseudoscientific if it fails to make any novel predictions of previously unknown phenomena, in contrast with scientific theories, which predict novel fact(s).[

26. Thagard critics of demarcation • The case of Cold fusion • A theory could meet all the previous criterion but still remain unscientific.

27. Thagard Criterion of demarcation

28. Step 1 • Determine the proposition you encounter is a theory, or a hypothesis.

30. Two different way