When arguing with someone in an attempt to get at an answer
or an explanation, 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:
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.
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.
argument from omniscience: (e.g., All people believe
in something. Everyone knows that.) An arguer would need omniscience
to know about everyone's beliefs or disbeliefs or about their
knowledge. Beware of words like "all," "everyone,"
"everything," "absolute."
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 you can gain little 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.
appeal to tradition (similar to the bandwagon fallacy):
(e.g., astrology, religion, slavery) just because people practice
a tradition, says nothing about its viability.
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 believes
in creation-science.) 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.
argument from adverse consequences: (e.g., We should
judge the accused as 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
that we should judge him guilty. (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.
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)
argumentum ad ignorantiam: A misleading argument used
in reliance on people's ignorance.
argumentum ad populum: An argument aimed to sway popular
support by appealing to sentimental weakness rather than facts
and reasons.
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 prove 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 that demons caused disease. The number
of believers say nothing at all about the cause of disease.
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 behavior?
circular reasoning: stating in one's proposition that
which one aims to prove. (e.g. God exists because the Bible says
so; the Bible exists because God influenced it.)
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 have consciousness
and human bodies and brains consist of atoms; therefore, atoms
have consciousness. Or: a word processor program consists of
many bytes; therefore a byte forms a fraction of a word processor.)
confirmation bias (similar to observational selection):
This refers to a form of selective thinking that focuses on evidence
that supports what believers already believe while ignoring evidence
that refutes their beliefs. Confirmation bias plays a stronger
role when people base their beliefs upon faith, tradition and
prejudice. For example, if someone believes in the power of prayer,
the believer will notice the few "answered" prayers
while ignoring the majority of unanswered prayers (which would
indicate that prayer has no more value than random chance at
worst or a placebo effect, when applied to health effects, at
best).
confusion of correlation and causation: (e.g., More
men play chess than women, therefore, men make better chess players
than women. Or: Children who watch violence on TV tend to act
violently 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).
excluded middle (or false dichotomy): considering only
the extremes. 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 either stands
guilty or not guilty.) Many times, a continuum occurs between
the extremes that people fail to see. The universe also contains
many "maybes."
half truths (suppressed evidence): An statement usually
intended to deceive that omits some of the facts necessary for
an accurate description.
loaded questions: embodies an assumption that, if answered,
indicates an implied agreement. (e.g., Have you stopped beating
your wife yet?)
meaningless question: (e.g., "How high is up?"
"Is everything possible?") "Up" describes
a direction, not a measurable entity. If everything proved possible,
then the possibility exists for the impossible, a contradiction.
Although everything may not prove possible, there may occur an
infinite number of possibilities as well as an infinite number
of impossibilities. Many meaningless questions include empty
words such as "is," "are," "were,"
"was," "am," "be," or "been."
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
non sequitur: Latin for "It does not follow."
An inference or conclusion that does not follow from established
premises or evidence. (e.g., there occured 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?
observational selection (similar to confirmation bias):
pointing out favorable 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
to install bells and whistles to announce the victors, while
the losers never get mentioned. This may lead one to conclude
that the chances of winning appear good while in actually just
the reverse holds true.
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.
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 haven't visited earth, etc.). Although one may prove non-existence
in special limitations, such as showing that a box does not contain
certain 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.
red herring: when the arguer diverts the attention
by changing the subject.
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
labeling of a group of people, come from abstract social constructs;
Astrology; god(s); Jesus; Santa Claus, etc.
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.
special pleading: the assertion of new or special matter
to offset the opposing party's allegations. A presentation of
an argument that emphasizes only a favorable 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 have no privilege to this knowledge. Or:
Horoscopes work, but you have to understand the theory behind
it.)
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.
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.
two wrongs make a right: trying to justify what we
did by accusing someone else of doing the same. (e.g. how can
you judge my actions when you do exactly the same thing?) The
guilt of the accuser has no relevance to the discussion.
Science attempts to apply some of the following criteria:
1) Skepticism 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 that would disprove a hypothesis
6) Uses descriptive language
7) Performs controlled experiments
8) Self-correcting
9) Relies on evidence and reason
10) Makes no claim for absolute or certain knowledge
11) Produces useful knowledge
cheers :) majere
roger m roeder
