Logical Fallacies — the Unstated Major Premise

Hey, guys. This post deals with the misuse of an otherwise valid informal argument, which borrows it’s logical structure from formal reasoning, a first-order Enthymeme, the abuse of this being known as the Unstated Major Premise.

In both forms, this is an argument in which a major assumption, evidence, premise, or reason that justifies the conclusion, is absent from the wording of the argument, and as long as both parties in an argument share the same semantic assumptions for the terminology employed in the argument, all is fine.

The problem arises when the two parties do not share the same assumptions going into the language used between them, and at least one of them fails to clarify to the other what those assumptions are, whether willfully or not. When this is used to arbitrarily misdefine a word, most often out of ignorance or confusion over its accepted meaning, it is known as a Humpty-Dumpty argument.

This is commonly done in debates with pseudoscientists, who either don’t know what they are talking about and are unaware of it, or with more savvy ones who intentionally use this as a rhetorical tactic to confuse their opponent and attempt to hide the fact that they don’t know what they are talking about unless their opponent calls them on it. This is often used in conjunction with a multiple untruth.

A brief list of words commonly mangled, folded, spindled and semantically mutilated by proponents of a variety of pseudosciences is as follows. There are of course many more:

• science
• religion
• evidence
• skeptic
• denier
• (true) believer
• (ad hoc) hypothesis
• logic
• reason
• theory
• model
• law
• reality
• objective
• closed-minded
• open minded
• fantasy
• revisionist
• straw man
• ad hominem
• scientism
• material
• atheist
• empirical
• peer-reviewed
• logical
• scientific
• energy
• vibration
• resonate
• frequency
• harmonic
• spiritual
• mind
• soul
• consciousness
• physical
• scientific method
• evolution
• scientist
• therapy
• natural
• organic
• dimension

A good example of this fallacy are evolution/creationism debates during which the claim is made that ‘there are no transitional species,’ when the creationist is using a different assumption from his opponent as to what constitutes a transitional species, often a sort of half-formed monstrosity ‘stuck’ between two other species in the fossil record, the oh-so 19th century notion of ‘one species crossing over into another’ fallacy, or the ‘dogs giving birth to kittens’ nonsense.

The major point here is that the creationist’s premise of what a transitional species is, an important bit of information in the argument, has been either overlooked or intentionally concealed from his opponent, the latter being the case with the more educated but willfully deceptive creationists, who often do this to keep from having to ever admit that they are mistaken, which just will not do if you’re a crusader for absolute truth. It’s referred to in some circles as ‘lying for Jesus.’

You might ask why I have been picking on the poor creationists here and there in this series of posts, and the primary reason is the fact that like I mentioned in a couple of other entries, creationists are fun because they are just such a wonderful source of logical fallacies, since they use all of them, and are continuously creating new ones often enough to make my head spin — Linda Blair style.

This endless creation (not the sort they’re trying to promote) of new ways for logic to go astray is just too useful for me to ignore, and yet another reason for me to be more alert for these errors in my own reasoning as well, so as to better introspect and avoid them in my thinking and arguments.

Rigorous self-examination is skeptical.

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