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Critical Thinking
Chapter 15
Science and Pseudoscience
Lecture Notes © 2008 McGraw Hill Higher
Education
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1 The Basic Pattern of
Scientific Reasoning
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Identifying the Problem: In order for science to be useful, the
problem will have to be “testable”; it can’t be unobservable.
Gathering Relevant Data: Sometimes, one observation will do
it but most often many observations are needed.
Formulating Hypotheses: Random data gathering won’t do;
you need an “educated guess” (hypothesis) to direct you.
Testing the Hypothesis:
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If it turns out that the universe isn’t a way which the hypothesis predicts,
the hypothesis is disconfirmed and we reject it.
However, the more of the world is observed to be like the hypothesis
predicts, the more confirmed the hypothesis will be.
But since we could never observe the whole universe—especially not
the future— no hypothesis will ever be proven.
Every time something falls to the ground, it adds conformation to the
theory of gravity. But it is always possible—although unlikely—that
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tomorrow things will start
“falling
up.”
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1.2 More on Hypothesis
Testing
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A Controlled Study: A study where a randomly
selected group is divided into a experimental
group and a control group, and only one group
is subject to the experimental condition.
Randomized Experimental Study: Find a group
that has already been exposed to the
experimental condition, and compare it to one
that has not but that is similar in all other
relevant respects.
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2 The Limitations of Science
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Science cannot answer:
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Questions of meaning: Does the universe or life
have a purpose? Does my suffering have
meaning?
Questions of value: Is abortion morally wrong? Is
freedom more important than equality?
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3 How to distinguish Science
from Pseudoscience.
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Pseudoscience is false science. It appears to be
science but is not.
Six marks of Pseudoscience
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It makes claims that are not testable.
It makes claims that are inconsistent with well-established
scientific truths.
It explains away or ignores falsifying data.
It uses vague language.
It is not progressive.
It often involves no serious effort to conduct research.
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3.1 Absence of Testability
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A claim (hypothesis) is testable when we can
make observations that would show it to be
true or false (i.e., when the hypothesis
“predicts” that the universe will be a certain
way).
Essentially it must be testable in principle. This
is only true if it is two things:
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Verifiable in principle: There is an observation that
would support it.
Falsifiable in principle: There is an observation that
would disconfirm it.
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3.1 Absence of Testability
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Pseudoscientists often fail to provide falsifiable
claims. They “explain away” any disconfirming
evidence. “Extrasensory perception exists, but
doesn’t work in the presence of skeptics.”
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All matter in the universe is moved by tiny elves
that always—when they are about to be
observed—hide. Could you observe anything to
prove this false?
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3.2 Explaining Away or
Ignoring Falsifying Evidence
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Pseudoscience will ignore falsifying evidence,
protecting “pet” theories.
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You caught the “telekinetic psychic” cheating on
camera? Well, he only cheats when his powers
aren’t working.
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3.3 Use of Vague Language
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Scientific hypotheses must be specific and make
specific predictions.
Cold reading: gathering obvious general information
about a subject and then repeating in a vague form
as if you “just knew it.” (e.g., psychic readings)
Fishing for Details:
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Multiple-out expressions: expressions so vague that an
interpretation of them is true of nearly anyone. (e.g.,
“someone close to you is having problems in his or her love
life.”)
Try-ons: something worded so that, if correct, it will be
remembered as “remarkable” but, if not, will be forgotten.
(e.g., I’m getting a feeling you may have some serious
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financial concerns.”)Lecture Notes ©Education
3.4 Lack of Progressiveness
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Science changes as hypothesis are confirmed
or shown false.
If a “science” has not changed for many years,
it is likely pseudoscience.
For example, people who still believe the earth
is flat.
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3.5 Failure to Conduct
Research
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Scientists are always driven to research—to make
observations that will either falsify or support their
theory.
If a “science” fails to do this, then it is a
pseudoscience.
Examples:
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The water cure theory. (They actually deny the need for
research.)
The flat earth theory. (If they really were concerned with the
truth, they would send up their own satellite to take pictures
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and prove that they Lecture
areNotes
right.)
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4 Case Study: Astrology
(Self-reading)
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Astrologers claim that human personality,
behavior, and destiny are all strongly
influenced by the position of the sun, moon,
planets, and stars at the time of one’s birth.
Astrology, however, has no scientific basis.
Let’s look at why…
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4.1 Astrology is
Pseudoscience because…
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Astrologers Fail to Identify a Plausible Physical
Force or Mechanism.
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The causal force used to be the “Greek gods,”
(what god you were “born under” made a
difference in your destiny).
No force that celestial bodies have—gravity,
magnetic field, etc. —produce a significant effect
on any earthy thing. (Your desk has more
gravitational effect on you than Venus.)
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4.2 Astrology is
Pseudoscience because…
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The Problem of Precession: As earth “wobbles”
in its orbit, the position of the stars change.
Astrologers have failed to compensate for this
fact.
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4.3 Astrology is
Pseudoscience because…
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Astrology is Not Progressive: it has not accounted for
new data.
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New planets have been discovered. They are now figured
into astrological calculations. However, shouldn’t they have
been before? Their effect is not contingent on our
awareness of them (so they claim). So shouldn’t have old
predictions been off?
There are other bodies (moons, asteroids) that are much
closer and/or bigger than other bodies that supposedly
have an effect (Pluto, Mercury). Why don’t these bigger
and/or closer bodies have an effect?
Constellations change over time. The stars that make up
the constellation Leo used to not look like a Lion, and later
won’t again. And yet the personality you have, if born under
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Leo, is somehow derived
the
fact that it looks like 15a
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lion?
4.4 Astrology is
Pseudoscience because…
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Astrology used Vague, Untestable Language.
“If you’re stubborn enough to keep going you
may still achieve your goals. The longer you
hang on, the more likely you are to achieve
your goals.”
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I “may”? This will be true no matter what happens.
It’s true by definition that the longer you do
something, the more likely you are to succeed.
This is so vague that it applies to pretty much
anyone.
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4.5 Astrology is
Pseudoscience because…
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If one’s destiny is set by the stars, there shouldn’t
be any “mixing of destinies.” If a Leo dies in an
accident one would expect many Leos to die in an
accident at the same time, but people of other
signs to be safe. But this is clearly not the case.
There were people of all signs aboard the Titanic—
yet they nearly all had the same fate. Seems like
what ship you decide to board has a lot more to do
with your destiny than where the stars, planets and
sun were when you were born.
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4.6 Astrology is
Pseudoscience because…
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Scientific Tests do not Support Astrology’s
Claims.
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Representative studies have been done comparing
sun signs (and other signs) to people’s
appearance, relationships, vocation, and
personality. None of them showed any correlation
between the two. (One could do just as well
predicting your personality by throwing darts at a
“personality dart board.”)
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Tutorial
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15.3, marked ones, any 5, individual
work
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