Logical razor

A logical razor is a short, rational principle used to shave off possible but unrealistic or unlikely explanations for a given phenomena. Common examples include Occam's razor and Alder's razor.

Common razors

Below is a short and non-comprehensive list of logical razors.

Occam's razor

For a more detailed treatment, see Occam's razor.

“	"Pluralitas non est ponenda sine neccesitate", or plurality should not be posited without necessity.	”
—William of Occam

Occam's razor was formulated by William of Occam. In short, it states that the hypothesis that makes the least assumptions is the best answer for the phenomena. Note that Occam's razor does not say that the more simple a hypothesis, the better.

Occam's duct tape

Also known as Occam's Krazy Glue or Occam's Stapler, this is pretty much the exact opposite of Occam's razor - it involves making as many unnecessary and irrelevant assumptions as possible.

Alder's razor

For a more detailed treatment, see Logical positivism.

This razor was formulated by Mike Alder and is better known by its correct name, Newton's flaming laser sword. It says that whatever cannot be settled by experimentation is not worth debate.

Crabtree's bludgeon

“	No set of mutually inconsistent observations can exist for which some human intellect cannot conceive a coherent explanation, however complicated	”
—Crabtree

Crabtree's bludgeon is an observation which serves as a foil to Occam's razor, characterizing a very different cognitive process exhibited in certain kinds of people.

Hanlon's razor

“	Never attribute to malice that which is adequately explained by stupidity.	”
—Robert J. Hanlon

This one's self-explanatory.

Grice's razor

“	As a principle of parsimony, conversational implications are to be preferred over semantic context for linguistic explanations.	”
—Grice, we think?

Basically, when in a conversation, prefer what the speaker meant over what the sentence she spoke literally meant.

Hume's razor

For a more detailed treatment, see David Hume.

“	If the cause, assigned for any effect, be not sufficient to produce it, we must either reject that cause, or add to it such qualities as will give it a just proportion to the effect.	”
—Hume

The cause must be proportionate to the effect it produces.

Hitchens's razor

For a more detailed treatment, see Christopher Hitchens.

“	Quod gratis asseritur, gratis negatur, or what can be asserted without evidence can be dismissed without evidence.	”
—Christopher Hitchens

This short-but-sweet razor asserts that the burden of proof regarding the truthfulness of a claim lies with the one who makes the claim and that if this burden is not met, the claim is unfounded and its opponents need not argue further in order to dismiss it.