Weak analogy

Definition

The arguer compares two or more things that aren't genuinely comparable.

Patterns:

A has characteristics a, b, c and d.

B has characteristics a, b, and c.

B probably has characteristic d, too.

.

A is x and y.

B is x and y.

C is x.

C is probably y, too.

Example

This ad for Proposition 8 ("One pair") commits the fallacy of weak analogy.

This animated ad features a man who has just returned home after purchasing a pair of shoes. He opens the shoe box to discover two left-footed shoes. He then returns to the store and protests to the salesman, "That's not a pair!" The salesman insists that he has two shoes and, therefore a pair. The man is angry and confused. He knows better. And so do we, the ad seems to say: just as two "same-side" shoes do not together make a pair, two "same-side" people do not together make a pair. The analogy, however, is weak. Shoes and people are not genuinely comparable. People, for example, are not ever made out of simili-suede.

Other Examples

This anti-smoking ad commits the fallacy of weak analogy. The arguer compares smoking cigarettes to picking your nose. n this ad there are two guys at a party checking out a "hot" girl. The girl starts picking her nose and the guys think that she's "hot," therefore she's cool, so they do the same thing. They start picking their nose. Then you see the people throughout the party all picking their noses. The bad habit of picking one's nose is being related to smoking cigarettes. Although it can be agreed that these are both bad habits, cigarette smoking is a risk to people's health. Bad habits and unhealthy habits are a weak comparison because there are more serious consequences to smoking than just picking your nose.

This video is of Governor Arnold Schwarzenegger giving a speech in which he uses a weak analogy. Governor Schwarzenegger compares melting firearms to the auto da fe of the Terminator in themovie, Terminator 2: Judgment Day. The argument seems to run: The Terminator was dangerous, could have been used to cause havoc, and needed to be destroyed so that the world wouldn't be eradicated.
Guns are dangerous and could be used to cause havoc.
Guns should probably be destroyed so that the world will not be eradicated. In this short video, Governor Schwarzenegger is giving a formal speech to an audience in Monterey Park, California. During this clip, the Governor discusses his plan to destroy firearms. Each person who turns in a firearm will receive a free t-shirt for their contributions. Once the guns are brought to a facility, they will be melted in order to make new items that will apparently be more beneficial to our state. Schwarzenegger then goes on to compare this to his movie, Terminator 2: Judgment Day. In the movie, Arnold's character, a killing machine from the future, realizes that he must be destroyed so that a research facility could not use the technology within him to greatly advance science, which would inevitably lead to the decimation of all life. Since the terminator cannot kill himself, he sacrifices himself by allowing John Connor, another main character, to lower him into a pool of molten metal, allowing humanity to survive. Schwarzenegger states that destroying firearms serves the exact same purpose as the terminator being destroyed: without guns, there will not be any more violence. Comparing these two situations together creates a weak analogy because first, the movie is completely fictional and shouldn't be compared to what Governor Schwarzenegger is trying to promote. Second, firearms are not the main root of violence; even if they were all destroyed, there are still hundreds of other things that could be used to kill a person.

This is an anti-smoking ad   which commits the same fallacy as above. If there is an analogy being drawn here, it is weak: there are important disnalogies between dogs and people. Moreover, smoking -- if both smoked -- would not cancel them. The ad seems to turn, rather, precisely on the fact that dogs and humans are dissimilar, in particular in terms of intelligence. It seems the punch line turns precisely on the lack of analogy: A dog is dumb and therefore has an excuse to do something dumb (smoke); a human is not like a dog (not dumb) and therefore has no excuse.