Summary #3 - "A Field Guide to Critical Thinking" James Lett

I'm not sure how "scholarly" this piece of literature is, but I found it to be very interesting and applicable to my topic. In this article, which was published in the Skeptical Inquirer in 1990, James Lett lists and elaborates on the steps necessary to thinking critically. For this, he uses the acronym FiLCHeRS.

The first step is that a claim must be Falsifiable. By this, he means that it must be possible that evidence exists that could prove a claim to be false. He indicates that if no evidence exists that could possibly disprove a claim, then the evidence that does exists supporting its validity is unimportant.

The second rule is Logic. If a claim is illogical (All dogs have fleas; Xavier has fleas; therefore Xavier is a dog), then it is not valid or sound. On the contrary, a claim can be valid but unsound: All dogs have fleas; Xavier is a dog; therefore Xavier has fleas.

The third guideline is Comprehensiveness. This is a simple rule, in that one must not only consider evidence that is supportive of a claim and discard evidence that may stand to disprove it. This would be unfair and invalid.

Fourth is Honesty. By this, Lett means not deluding one's self if evidence does not support their particular opinion. If evidence points to a claim being true, then it must be believed as such. If evidence points to a claim being false, then it must be believed as such.

Fifth is Replicability. This rule is simple, in that the results of a hypothesis must be replicable, meaning they much occur more than once. If this is not the case, then the results point to the event in question as being due to coincidence.

Finally, is Sufficiency. For this, Lett offers three sub-guidelines:

1. the burden of proof for any claim rests on the claimant,

-This means that just because a claim cannot be disproved does not me that it has been proved (UFOs)

2. extraordinary claims demand extraordinary evidence, and

-If you make an extraordinary claim, you must have equally extraordinary evidence. Lett uses the example: "If I claim that it rained for ten minutes on my way to work last Tuesday, you would be justified in accepting that claim as true on the basis of my report. But if I claim that I was abducted by extraterrestrial aliens who whisked me to the far side of the moon and performed bizarre medical experiments on me, you would be justified in demanding more substantial evidence. "

3. evidence based upon authority and/or testimony is always inadequate for any paranormal claim

-this simply means that people can lie. Even experts.