(In the list below a few examples are given in relationship to
religion and (in blue) sexism though where examples are not given does
not imply that they do not apply).
"You don't need to take drugs to hallucinate;
improper language can fill your world with phantoms and spooks of many
kinds."
-Robert A. Wilson
When arguing with someone in an attempt to get at an
answer or an explanation to a theory, you may come across a person who
makes logical fallacies. Such discussions may prove futile. You might
try asking for evidence and independent confirmation or provide other
hypothesis that give a better or simpler explanation. If this fails,
try to pinpoint the problem of your arguer's position. You might spot
the problem of logic that prevents further exploration and attempt to
inform your arguer about his fallacy. The following briefly describes
some of the most common fallacies:
1. Ad hominem: Latin for "to the man."
An arguer who uses ad hominems attacks the person instead of the
argument. Whenever an arguer cannot defend his position with evidence,
facts or reason, he or she may resort to attacking an opponent either
through: labeling, straw man arguments, name calling, offensive
remarks and anger.
2. Appeal to ignorance (argumentum ex
silentio) appealing to ignorance as evidence for something. (e.g., We
have no evidence that God doesn't exist, therefore, he must exist. Or:
Because we have no knowledge of alien visitors, that means they do not
exist). Ignorance about something says nothing about its existence or
non-existence.
3. Argument from omniscience: (e.g., All
people believe in something. Everyone knows that.) An arguer would
need to be omniscient to know about everyone's beliefs or disbeliefs
or about their knowledge. Beware of words like "all,"
"everyone," "everything," "absolute."
4. Appeal to faith: (e.g., if you have no
faith, you cannot learn) if the arguer relies on faith as the bases of
his argument, then nothing more can be gained from further discussion.
Faith, by definition, relies on a belief that does not rest on logic
or evidence. Faith depends on irrational thought and produces
intransigence.
5. Appeal to tradition (similar to the bandwagon
fallacy): (e.g., astrology, religion, slavery) just because people
practice a tradition, says nothing about its viability
6. Argument from authority (argumentum ad
verecundiam): using the words of an "expert" or authority as
the bases of the argument instead of using the logic or evidence that
supports an argument. (e.g., Professor so-and-so says creation-science
is correct.) Simply because an authority makes a claim does not
necessarily mean he got it right. If an arguer presents the testimony
from an expert, look to see if it accompanies reason and sources of
evidence behind it.
7. Argument from adverse consequences: (e.g.,
The accused must be found guilty, otherwise others will commit similar
crimes) Just because a repugnant crime or act occurred, does not
necessarily mean that a defendant committed the crime or should be
sentenced. (Or: disasters occur because God punishes non-believers;
therefore, we should all believe in God) Just because calamities or
tragedies occur, says nothing about the existence of gods or that we
should believe in a certain way.
8. Argumentum ad baculum: An argument based on
an appeal to fear or a threat. (e.g., If you don't believe in God,
you'll burn in hell)
9. Argumentum ad ignorantiam: A misleading
argument used in reliance on people's ignorance .
10. Argumentum ad populum: An argument aimed to
sway popular support by appealing to sentimental weakness rather than
facts and reasons.
11. Bandwagon fallacy: concluding that an
idea has merit simply because many people believe it or practice it.
(e.g., Most people believe in a god; therefore, it must be true.)
Simply because many people may believe something says nothing about
the fact of that something. For example many people during the Black
plague believed it was caused by demons. The number of believers say
nothing about the cause of disease.
12. Begging the question (or assuming the
answer): (e.g., We must encourage our youth to worship God to instill
moral behavior.) But does religion and worship actually produce moral
behaviour?
13. Circular reasoning: stating in one's proof
that which one is supposed to be proving. (e.g. God exists because the
Bible says so; the Bible exists because God influenced it.)
14. Composition fallacy: when the conclusion
of an argument depends on an erroneous characteristic from parts of
something to the whole or vice versa. (e.g., Humans are conscious and
are made of atoms; therefore, atoms have consciousness. Or: a word
processor program consists of many bytes; therefore a byte is a
fraction of a word processor.)
15. Confusion of correlation and causation:
(e.g., More chess players are men, therefore, men make better chess
players than women. Or: Children who watch violence on TV tend to
become violent when they grow up.) But does television programming
cause violence or do violence oriented children prefer to watch
violent programs? Perhaps an entirely different reason creates
violence not related to television at all. Stephen Jay Gould called
the invalid assumption that correlation implies cause as
"probably among the two or three most serious and common errors
of human reasoning" (The Mismeasure of Man).
16. False dichotomy: considering only the
extremes excluding middle. Many people use Aristotelian either/or
logic tending to describe in terms of up/down, black/white,
true/false, love/hate, etc. (e.g., You either like it or you don't.
He's either guilty or not guilty.) Many times, a continuum occurs
between the extremes that people fail to see. The universe also
contains many "maybes."
17. Half truths (suppressed evidence): A
statement usually intended to deceive that omits some of the facts
necessary for an accurate description.
18. Loaded questions: embodies an assumption
that, if answered, indicates an implied agreement. (e.g., Have you
stopped beating your wife yet?)
19. Meaningless question: (e.g., How high is up?
Is everything possible?) "Up" describes a direction, not a
measurable entity. If everything were possible, then it would be
possible for the impossible, a contradiction. Although everything may
not be possible, there may be an infinite number of possibilities as
well as an infinite number of impossibilities.
20. Misunderstanding the nature of statistics:
(e.g., the majority of people in the United States die in hospitals,
therefore, stay out of them.) "Statistics show that of those who
contract the habit of eating, very few survive." -- Wallace Irwin
21. Non sequitur: Latin for "It doesn't
follow." An inference or conclusion that does not follow from
established premises or evidence. (e.g., there was an increase of
births during the full moon. Conclusion: full moons cause birth rates
to rise.) But does a full moon actually cause more births, or did it
occur for other reasons, perhaps from expected statistical variations?
False premis, false conclusion.
22. Observational selection: pointing out
favourable circumstances while ignoring the unfavorable. Anyone who
goes to Las Vegas gambling casinos will see people winning at the
tables and slots. The casino managers make sure there's bells and
whistles to announce the victors, while the losers are never
mentioned. This may lead one to conclude that the chances of winning
are good while in actually just the reverse is true.
23. Post hoc, ergo propter hoc: Latin for
"It happened after, so it was caused by." Similar to a non
sequitur, but time dependent. (e.g. She got sick after she visited
China, so something in China caused her sickness.) Perhaps her
sickness derived from something entirely independent from China.
24. Proving non-existence: when an arguer cannot
provide the evidence for his claims, he may challenge his opponent to
prove it doesn't exist (e.g., prove God doesn't exist; prove UFO's
aren't real, etc.). Although one may prove non-existence in special
limitations, such as showing that a box does not contain items, one
cannot prove universal or absolute non-existence, or non-existence out
of ignorance. One cannot prove something that does not exist. The
proof of existence must come from those who make the claims.
25. Red herring: when the arguer diverts the
attention by changing the subject.
(Insert) reductio ad absurdum
26. Reification fallacy: when people treat an
abstract belief or hypothetical construct as if it represented a
concrete event or physical entity. Examples: IQ tests as an actual
measure of intelligence; the concept of race (even though genetic
attributes exist), from the chosen combination of attributes or the
labelling of a group of people, come from abstract social constructs;
Astrology; god(s); Jesus; Santa Claus.
27. Slippery slope: a change in procedure,
law, or action, will result in adverse consequences. (e.g., If we
allow doctor assisted suicide, then eventually the government will
control how we die.) It does not necessarily follow that just because
we make changes that a slippery slope will occur.
28. Special pleading: the assertion of new or
special matter to offset the opposing party's allegations. A
presentation of an argument that emphasises only a favourable or
single Aspect of the question at issue. (e.g. How can God
create so much suffering in the world? Answer: You have to understand
that God moves in mysterious ways and we are not privileged to this
knowledge. Or: Horoscopes work, but you have to understand the theory
behind it.)
29. Statistics of small numbers: similar to
observational selection (e.g., My parents smoked all their lives and
they never got cancer. Or: I don't care what others say about Yugos,
my Yugo has never had a problem.) Simply because someone can point to
a few favorable numbers says nothing about the overall chances.
30. Straw man: creating a false scenario and
then attacking it. (e.g., Evolutionists think that everything came
about by random chance.) Most evolutionists think in terms of natural
selection which may involve incidental elements, but does not depend
entirely on random chance. Painting your opponent with false colors
only deflects the purpose of the argument.
31.
Two wrongs make a right: trying to justify what we did by accusing
someone else of doing the same. (e.g. who are you to judge my actions
when you do exactly the same thing?) The guilt of the accuser is
irrelevant to the discussion.
Science attempts to apply some of the following
criteria:
1) Scepticism of unsupported claims 2) Combination of
an open mind with critical thinking 3) Attempts to repeat experimental
results. 4) Requires testability 5) Seeks out falsifying data 6) Uses
descriptive language 7) Performs controlled experiments 8)
Self-correcting 9) Relies on evidence and reason 10) Produces useful
knowledge
Pseudo-science and religion relies on some of the
following criteria
1) Has a negative attitude to scepticism 2) Does not
require critical thinking 3) Does not require experimental
repeatability 4) Does not require tests 5) Does not accept falsifying
data 6) Uses vague language 7) Relies on anecdotal evidence 8) No
self-correction 9) Relies on belief and faith 10) Produces no useful
knowledge
Some of this information derived in part from: William
D. Gray, "Carl Sagan, "," Random House, New York, 1995
Houghton Mifflin Company