PCT - C10 - Judging Scientific Theories
Summary
Science and Not Science
• Science
seeks knowledge and understanding of reality, and it does so through die
formulation, testing, and evaluation of theories. Science is a way of searching
for truth.
• Science
is not a worldview, and we can't identify it with a particular ideology.
Science is also not scientism—it is not the only way to acquire knowledge. It
is, however, a highly reliable way of acquiring knowledge of empirical facts.
• Tht:
scientific method cannot be identified with any particular set of experimental
or observational procedures. But it does involve several general steps: (1)
identifying the problem, (2) devising a hypothesis, (3) deriving a test
implication, (4) performing the test, and (5) accepting or rejecting the
hypothesis.
• No
hypothesis can be conclusively confirmed or confuted. But this fact does not
mean that all hypotheses are equally acceptable.
• Following
the steps of the scientific method, scientists test hypotheses in many fields,
including medical science. One example is the testing of the hypothesis that
taking high doses of vitamin C can cure cancer.
• To
minimize errors in testing, scientists use control groups, make studies double-blind,
include placebos in testing, and seek replication of their work.
• Theory-testing
is part of a broader effort to evaluate a theory against its competitors. This
kind of evaluation always involves, implicitly or explicitly, the criteria of
adequacy.
• The
criteria are testability, fruitfulness, scope, simplicity, and conservatism.
• The
criteria of adequacy played a major role in settling the historic debate about
planetary motion, and they are used today to effectively judge the relative
merits of the theories of evolution and creationism.
• Inference
to the best explanation can be used to assess weird theories as well as more
commonplace explanations in science and everyday life.
• Scientifically
evaluating offbeat theories can often be worthwhile in determining their truth
or falsity and (sometimes) in discovering new phenomena.
* When people try to evaluate extraordinary theories, they
often make certain typical mistakes. They may believe that because they can't
think of a natural explanation, a paranormal explanation must be correct. They
may mistake what seems for what is, forgetting that we shouldn't accept the
evidence provided by personal experience if we have good
reason to doubt it. And they may not fully understand the concepts of logical
and physical possibility.
• The
distinction between logical and physical possibility is crucial. Some things
that are logically possible may not be physically possible, and things that are
physically possible may not be actual.
Judging Weird Theories
• In both
science and everyday life, the TEST formula enables us to fairly appraise the
worth of all sorts of weird theories, including those about crop circles and
communication with the dead, the two cases examined in this chapter.
@ Field Problems
1. Find a
controversial health or medical theory on the Internet and design a study hi
test it. Indicate the makeup and characteristics of any group in the study,
whether a placebo group is used, whether the study is doubleblind, and what
study results would confirm and disconfirm the theory.
2. Find a
controversial theory in die social sciences on the Internet and design a study
to test it. Indicate the makeup and characteristics of any group in the study,
whether a placebo group is used, whether the study is doubleblind, and what
study results would confirm and disconfirm the theory. If the theory is one
that you strongly believe, indicate the kind and level of evidence that could
convince you to change your mind about it.
3. Do
research on the Internet to find information on spontaneous human combustion,
the theory that a human body can catch on fire due to an unknown internal
chemical or biological process. Apply the TEST formula to evaluate the theory.
Consider at least one plausible alternative theory. Look for background
information at The Skeptic's Dictionary (http://skepdic.com),
the Committee for the Scientific Investigation