Philosophy of the Sciences, Lecture 5

1. Philosophy of the Sciences, Lecture 5 Troubles with Falsificationism and Thagard’s Answer to the Demarcation Problem maxdeutsch@hkusua.hku.hk

2. Review, Lecture 3 • We’re trying to arrive at an answer to the question of what marks science off from non-science—an answer to the “demarcation problem”. • The question is intrinsically interesting, of practical importance (Who gets the money?) and crucial to understanding the value of science (Why is science particularly valuable?).

3. The answers to the demarcation problem that initially come to mind seem to characterize science but not define it. • Popper’s view is that science isn’t science because its theories are confirmed—“confirming instances” of a theory are too easy to come by. Instead, science is science because its theories are falsifiable. They’re inconsistent with some possible occurrences; they make risky predictions. • Einstein’s theory of relativity is falsifiable, but Marx’s theory of history and Freud’s and Adler’s psychological theories are not. (acc. to Popper)

4. Being true is irrelevant to being science (according to the falsificationist criterion).

5. Review, Lecture 3 • Some consequences and corollaries of Popper’s solution to the demarcation problem: • Theories not falsifiable by any conceivable event are not scientific. (Thus, the naïve view that science strives for irrefutability gets things exactly the wrong way around.) • Every good scientific theory is a prohibition--it denies that certain things may happen.

6. A test of a theory is an attempt to falsify it. • Some genuinely falsifiable theories, when falsified, are maintained by their admirers either by re-casting the theory or adding auxilliary assumptions. Such a procedure is always possible, but it rescues the theory only by destroying or reducing the theory’s claim to scientific status. (Popper calls such rescue operations conventionalist twists.) • End review, begin Lecture 4 • Popper on induction:

7. Many would say that science is distinguished from non-science by its reliance on “the scientific method”—a method that involves observation, experiment, and, crucially, a certain kind of inference or reasoning: Inductive inference. It is a scientific law that water boils at 100 degrees. How is the law established? Standard answer: By observation. Given a sufficient number of observations and we take the law to hold.

8. But there is a problem with this standard answer and a related problem with taking the inductive method as a solution to the demarcation problem. It is possible that the law is false even given the numerous observations. The law “transcends experience”—it has consequences with respect to the way unobserved water would behave if heated to 100 degrees. So, the observational evidence cannot on its own justify the law.

9. If we add to this the facts that: (ii) Science depends on the establishment of scientific laws (iii) In science, only observation and experiment may decide upon the acceptance or rejection of scientific claims, including claims about laws …we have what appears to be a very vexing problem. Popper’s solution: There is no conflict. Laws are not inferred from observational evidence. They are simply conjectures.

10. The Troubles with Falsificationism (Trouble 1) A counterintuitive consequence of falsificationism is that it puts no methodological constraints on theory-construction in science. A theory is scientific just in case it is falsifiable, nothing more, nothing less. It follows that if I have a vivid dream in which a falsifiable theory occurs to me (about, say, the origin of the species) that theory is scientific, despite the fact that I merely dreamed it up.

11. I needn’t run any experiments, nor make even a single observation of the empirical world!

12. Troubles with Falsificationism (cont.) (Trouble 2) As Popper himself notes, even theories that are falsifiable, and look, at first, to be falsified, can be saved by a “conventionalist twist”. Popper describes such twists as “ad hoc”, as maneuvers that have no rationale except to save the theory. And, surely some of them are.

13. But, equally surely, some of them aren’t. There are cases in which a risky prediction is the result of an inessential part of the theory—a part that can simply be dropped without giving up on the core. Lamarkian vs. Darwinian Selection

14. (Trouble 2 cont.) And there are cases in which auxiliary assumptions whose addition will help a theory avoid falsification should be added to the theory, perhaps because the theory, so modified, fits smoothly with other going theories, or because the theory, unmodified, fails take account of certain phenomena relevant to the domain that the theory covers. Is trouble 2 really all that worrisome?

15. A modified falsificationism: A theory is scientific just in case it is falsifiable and capable of being rescued from falsification only by a well-motivated conventionalist twist. New troubles? (Trouble 3) Some theories that are pretty clearly unscientific, astrology e.g., appear to be falsifiable! Popper claims that the predictions of the astrologist are so vague that no conceivable course of experience would refute them.

16. But, as Thagard points out, these vague predictions are vaguely testable. Astrologists claim, for example, that people born under certain signs or planets are more likely to adopt certain occupations rather than others. Gauquelin’s finding: No statistically significant correllation between careers and either sun sign, moon sign, or ascendant sign.

17. What’s interesting about Gauquelin’s finding is not that it falsified astrology. That was to be expected. What’s interesting is that astrology is falsifiable. Since it’s falsifiable, it’s science, acc. to Popper’s criterion.

18. Bok’s criticisms: (1) Astrology arose from a magical world-view. (2) Planets too distant for there to be a physical foundation to astrology (3) People believe in it out of a longing for comfort Re: (1): chemistry sprang from alchemy; mystical influences in Newton and Einstein.

19. Re: (2): Other scientific views without physical foundations: the theory of continental drift. Link btw. smoking and cancer. Re: (3): Why people believe even the best scientific theories ought to be irrelevant to their status as science. Thagard’s proposal: A solution to the demarcation problem requires looking to social and historical context.

20. The social factors--consider the community of practitioners… Do they agree upon the principles and problem-solving strategies of the theory? Do they care about anomalies? Do they compare theirs to other competitor theories? Do they actively attempt confirmation or disconfirmation?

21. The historical factors: Consider the past life of the theory… Has it tried to explain new facts and deal with anomalies? Has it fared well in competition with other theories?

22. Thagard’s socio-historical solution to the demarcation problem: A theory is pseudoscientific if and only if (a) it has been less progressive than other theories and faces unsolved problems and (b) its practitioners don’t develop the theory, they show no concern for how the theory fares in relation to others, and they are selective in considering confirmations and disconfirmations.

23. Why astrology fails the test: • It’s dramatically unprogressive. • There are outstanding problems. • There are alternative theories of behavior. • Its practitioners are generally unconcerned with solving its problems and dealing with competitor theories.

24. A consequence of Thagard’s solution: • Whether something counts as science or pseudoscience is socially and historically relative. • On the historical side, as Thagard points out, according to his criterion, what once was science can become pseudoscience. In fact, this is precisely what happened to astrology…or so Thagard says. He defends this claimed historical relativity by claiming that rationality itself is historically relative.

25. On the social side, do isolated astrologists count as scientists; is astrology science for them? And what exactly is the scope of “alternative theories”? Should we be worried that our best theories are in fact pseudoscientific since they match up poorly with the best Martian theories?