Monthly Archives: May 2010

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 or suppressed major premise.

This is an argument in which a major assumption, evidence, premise, or reason used to justify the conclusion is absent from the argument’s wording, and as long as both parties in an argument share the same semantic assumptions for the terms used in the argument, all is fine.

The problem begins when the two parties do not share the same assumptions going into their language, 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.

It’s 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 use this as a rhetorical tactic to confuse their opponent 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
  • transitional form/fossil/species

A good example of this 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 it means, 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.

Crocoducks, anyone?

The major point here is that the creationist’s idea 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.

You might ask why I’m 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 to be more alert for these errors in one’s own reasoning as well, so as to better introspect and avoid them in one’s thinking and arguments.

Rigorous self-examination is skeptical.

Enhanced by Zemanta

Teh Funneh Kittehs, Dey Run Amok…

Astronomy Pix of the Week

Rho Ophiuchi Wide Field

Looking Back Across Mars

Clouds and Stars over Cotopaxi Volcano in Equador

M13, the Great Globular Cluster in Hercules

Atlantis over Rhodes

Teh Itteh Bitteh Kitteh…Wif Teh Byg Miaow

My Favorite Deadly Sin Given Life…Sloths!


Get every new post delivered to your Inbox.

Join 3,080 other followers

%d bloggers like this: