Science versus Pseudo-science:
The problem of demarcation
Alireza Monajemi, MD-PhD
Philosophy of Science Department,
Institute for Humanities and Cultural Studies
4/13/2015
The importance of the problem
Clinical setting
Certification
Research
4/13/2015
What is science?
4/13/2015
The straightforward answer
Biology
Physics
Medicine
Science
4/13/2015
• we are asking what common features all the
things on that list share?
=
• what it is that makes something a science?
4/13/2015
The problem of demarcation
Science
Pseudoscience
4/13/2015
• 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
4/13/2015
Philosophy of science on the
problem of demarcation
4/13/2015
Vienna
circle
4/13/2015
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 theoryconstruction have enabled scientists to
unravel so many of nature's secrets.
4/13/2015
Vienna circle
• Meaningfulness (tautology v.s empirical)
• Verification
• Sense data
4/13/2015
Fact, hypothesis and theories
4/13/2015
Theory
• Theory is a conceptual framework that
explains existing observations and predicts
new ones.
• It can incorporate facts, laws, inferences, and
tested hypotheses
4/13/2015
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.
4/13/2015
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.
4/13/2015
Popper
• Two major criticisms of Vienna circle’s
criterion of demarcation:
• The problem of induction (Russell story)
• Exclusion of scientific theories
4/13/2015
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.
4/13/2015
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.
4/13/2015
Popper’s criterion of demarcation
• it must be possible for an empirical
scientific system to be refuted by
experiment.
4/13/2015
4/13/2015
Science
4/13/2015
Pseudoscience
e.g. Marxism or
psychoanalysis
Popper versus Vienna circle
• Vienna circle
• Popper
• Meaningfulness
• Meaningfulness
• Empiric
• Empiric
• Verifiability
• Falsifiability
• Exclusion of theories
• Inclusion of theories
4/13/2015
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.
4/13/2015
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.
4/13/2015
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).[
4/13/2015
Thagard critics of demarcation
• The case of Cold fusion
• A theory could meet all the previous criterion
but still remain unscientific.
4/13/2015
Thagard Criterion of demarcation
Research
group
Grant holders and
policy makers
Public
Scientific
community
4/13/2015
Step 1
• Determine the proposition you
encounter is a theory, or a
hypothesis.
4/13/2015
Meaningful
Empiric
Falsifiable
Progressive
Authentic
4/13/2015
Two different way
Traditional
medicine
4/13/2015
As a theory
As a
hypothesis