The following are suggested as tools
for testing arguments and detecting
fallacious or fraudulent arguments.
Although written from a physical scientist's
standpoint, they (especially the "common
fallacies") are relevant to any rational
argument or enterprise :
Wherever possible there must
be independent confirmation of the facts
Encourage substantive debate on the evidence
by knowledgeable proponents of all points of
view.
Arguments from authority carry little weight
(in science there are no "authorities").
Spin more than one hypothesis - don't simply
run with the first idea that caught your fancy.
Try not to get overly attached to a hypothesis
just because it's yours.
Quantify, wherever possible.
If there is a chain of argument every link
in the chain must work.
"Occam's razor" - if there are two hypothesis
that explain the data equally well choose the
simpler.
Ask whether the hypothesis can, at least
in principle, be falsified (shown to be false
by some unambiguous test). In other words, it
is testable? Can others duplicate the experiment
and get the same result?
Additional issues
are
Conduct control experiments - especially
"double blind" experiments where the person
taking measurements is not aware of the test
and control subjects.
Check for confounding factors - separate
the variables.
Common fallacies
of logic and rhetoric
Ad hominem - attacking the arguer
and not the argument.
Argument from "authority".
Argument from adverse consequences (putting
pressure on the decision maker by pointing out
dire consequences of an "unfavourable" decision).
Appeal to ignorance (absence
of evidence is not evidence of absence).
Special pleading (typically referring to
god's will).
Begging the question (assuming an answer
in the way the question is phrased).
Observational selection (counting the hits
and forgetting the misses).
Statistics of small numbers (such as drawing
conclusions from inadequate sample sizes).
Misunderstanding the nature of statistics
(President Eisenhower expressing astonishment
and alarm on discovering that fully half of
all Americans have below average intelligence!)
Inconsistency (e.g. military expenditures
based on worst case scenarios but scientific
projections on environmental dangers thriftily
ignored because they are not "proved").
Non sequitur - "it does not follow"
- the logic falls down.
Post hoc, ergo propter hoc - "it
happened after so it was caused by" - confusion
of cause and effect.
Meaningless question ("what happens when
an irresistible force meets an immovable object?).
Excluded middle - considering only the two
extremes in a range of possibilities (making
the "other side" look worse than it really is).
Short-term v. long-term - a subset of excluded
middle ("why pursue fundamental science when
we have so huge a budget deficit?").
Slippery slope - a subset of excluded middle
- unwarranted extrapolation of the effects (give
an inch and they will take a mile).
Confusion of correlation and causation.
Straw man - caricaturing (or stereotyping)
a position to make it easier to attack..
Suppressed evidence or half-truths.
Weasel words - for example, use of euphemisms
for war such as "police action" to get around
limitations on Presidential powers. "An important
art of politicians is to find new names for
institutions which under old names have become
odious to the public"