Transcript Lecture 4: Troubles With Falsificationism and

Philosophy of the Sciences,
Lecture 5
Troubles with Falsificationism and
Thagard’s Answer to the Demarcation
Problem
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Review, Lecture 3
•We’re trying to arrive at an answer to the
question of what marks science off from nonscience—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?).
•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)
•Being true is irrelevant to being science
(according to the falsificationist criterion).
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.
•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:
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.
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.
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.
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.
I needn’t run any experiments, nor make even a
single observation of the empirical world!
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.
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
(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?
A modified falsificationism: A theory is scientific
just in case it is falsifiable and capable of being
rescued from falsification only by a wellmotivated 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.
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.
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.
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.
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.
The social factors--consider the community of
practitioners…
Do they agree upon the principles and problemsolving strategies of the theory?
Do they care about anomalies?
Do they compare theirs to other competitor
theories?
Do they actively attempt confirmation or
disconfirmation?
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?
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.
Why astrology fails the test:
1. It’s dramatically unprogressive.
2. There are outstanding problems.
3. There are alternative theories of behavior.
4. Its practitioners are generally unconcerned with
solving its problems and dealing with competitor
theories.
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.
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?