James Lett
Indian River Community College
&
Drew Hurley
Santa Fe Community College
.
Social Problems
SYG 2010
All conceptual material for this program comes from:
Lett, James. 'A Field Guide To Critical Thinking.' SKEPTICAL INQUIRER, Winter 1990, 14: 153-160.
James Lett is Associate Professor of Anthropology at Indian River Community College.
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F i L C H e R S
FALSIFIABILITY -- It must be possible to conceive of evidence that would prove the claim to be false.
False Examples:
'The Moon is made of green cheese.' This claim can be proven to be false
'God is dead.' This claim is not falsifiable. It must be accepted, or not, on the basis of faith and personal belief.
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True Examples:
'The life span of humans is less than 200 years.' This claim would be proven false if anyone lived to be 200 years old.
'What will be, will be.' This is a truism that is so non-specific as to be meaningless.
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LOGIC -- Any argument offered as evidence in support of any claim must be sound.
Can you imagine an instance where the stated conclusion would not follow?
All dogs have fleas.
Xavier has fleas.
Therefore, Xavier is a dog.
Example: Could Xavier be a cat?
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COMPREHENSIVENESS -- The evidence offered in support of any claim must be exhaustive; that is, all of the available evidence must be considered. Important, even obvious, sources of data cannot be ignored.
There are no married students in my noon class. Therefore, there are no married students at this college.
There are no atheists in my home town church. Therefore, there are no atheists in my home town.
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HONESTY -- The evidence in support of any claim must be evaluated without self-deception. If the weight of the evidence falsifies your belief, then you must conclude that your belief is false, and face the implications of that conclusion forthrightly.
Do Not deceive yourself.
Do not deceive others.
REPLICABILITY -- If the evidence for any claim is based upon an experimental
result, or if the evidence offered in support of any claim could logically be explained as coincidental,
then it is necessary fo the evidence to be reproduced in subsequent experiments or trials.
The rule of replicability requires independent observers to follow the same procedures
and achieve the same results as the original claimants.
Examples: The inability to replicate 'cold fusion.'
The inability to substantiate the results of Cyril Burt's twins study.
SUFFICIENCY -- The evidence offered in support of any claim must be adequate to
establish the truth of that claim, with these stipulations: (1) the burden of proof for any claim rests on
the claimant, (2) extraordinary claims demand extraordinary evidence, and (3) evidence based upon
authority and/or testimony is always inadequate for any extraordinary claim.
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Examples of Sufficiency:
UFO claims require physical evidence for there to be sufficiency.
Despite persistent rumors, there is no evidence that Adolf Hitler is alive in Argentina
The first three rules of F i L C H e R S -- Falsifiability, Logic, and Comprehensiveness -- are all logically necessary rules of evidential reasoning.
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The last three rules of F i L C H e R S -- Honest, Replicability, and Sufficiency -- are all pragmatically necessary rules of evidential reasoning.
The purpose of this field guide is to emphasize the importance of learning to think and reason based upon empirical evidence. Passing all six F i L C H e R S tests does not guarantee that a claim is true, but it does mean that you will ahve good reasons of believing that claim.
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As a responsible adult, you may be required to change your beliefs tomorrow, and you
should be willing and able to do so if, and only if, the evidence warrants it.
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drewhurley@claw.org
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All conceptual material for this program comes From:
Lett, James. 'A Field Guide To Critical Thinking.' SKEPTICAL INQUIRER. Winter 1990,
14: 153-160.
Produced at Santa Fe Community College, 1998
Program Designed and Created by:
Drew Hurley
Santa Fe Community College
3000 NW 83rd Street
Gainesville, FL 32606
ClipArt provided by:
Imageline, Inc.
401 East Main Street, Suite 100
Richmond, VA 23219
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'A Field Guide To Critical Thinking'
Go To Beginning Of This Program
Go To Social Problems Resources Page