Tag Archives: Guilt by association

The Slippery Slope

by Tim Harding

A slippery slope argument may or may not be a fallacy, depending on whether the argument is logical.  The argument typically states that a relatively small first step will inevitably lead to a chain of related events culminating in some significant consequence, much like an object given a small push over the edge of a slope will slide all the way to the bottom.  


A slippery slope argument has the following form:

Premise: Event X has occurred (or will or might occur).

Conclusion: Therefore consequence Y will inevitably happen.

The strength of such an argument depends on whether or not one can demonstrate a chain of cause and effect leading to the significant consequence.  If no such chain can be demonstrated, the argument becomes a fallacy. This is especially so in cases in which there is a significant number of steps or gradations between one event and another, which increases the probability of the chain of cause and effect being broken. On the other hand, if the chain of cause and effect can be adequately demonstrated to be unbroken, the argument is logical.

The fallacious form of this argument has traditionally been called The Camel’s Nose, because of the image of a sheik whose camel sticks its nose into his tent on a cold night.  The idea is that the sheik is afraid to let the camel put its nose into the tent because once the beast puts in its nose, it will inevitably put in its head, and then its neck, and eventually its whole body.[1] However, this sort of thinking does not allow for any possibility of stopping the process. It simply assumes that, once the nose is in, the rest must follow — that the sheik can’t stop the progression once it has begun — and thus the process is inevitable.[2]

Camel's Nose

For instance, if one were to argue,

“If we allow the government to infringe upon our right to privacy on the Internet, it will then feel free to infringe upon our privacy on the telephone. After that, FBI agents will be reading our mail. Then they will be placing cameras in our houses. We must not let any governmental agency interfere with our Internet communications, or privacy will completely vanish in the United States.”

Such thinking is fallacious; no logical proof has been provided yet that infringement in one area will necessarily lead to infringement in another, no more than a person buying a single can of Coca-Cola in a grocery store would indicate the person will inevitably go on to buy every item available in the store, helpless to stop herself.[2]

A currently topical example is that one of the arguments against same-sex marriage is that it will lead to a demand for the adoption of children by same-sex married couples.  It is argued that such a demand will be difficult to resist under anti-discrimination legislation; and so the way to prevent such adoptions is to resist same-sex marriage.  There are arguments for and against the need for children to have a relationship with both and father and a mother, but these arguments are not critical to whether or not the slippery slope argument is fallacious.  If there will be no irresistable demand for the adoption of children by same-sex married couples, then the slippery slope argument is clearly fallacious in this case.

Notes and references

[1] The Camel’s Nose fallacy is sometimes described as being based on an old Arabian fable or proverb; however this provenance is doubtful. It is more likely to be a Victorian English invention.

[2] Makethestand.com Learning to Reason Clearly by Understanding Logical Fallacies. Posted 19/7/07. Viewed 9/3/14.

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Filed under Logical fallacies

Three more fallacies of relevance

by Tim Harding

Fallacies are patterns of reasoning that are logically incorrect.  They apply to arguments rather than isolated statements or propositions.  Arguments are logically valid or invalid, whereas propositions are true or false. The fallacies of relevance, for example, clearly fail to provide adequate reason for believing the truth of their conclusions.  Although they are often used in attempts to persuade people by non-logical means, only the unwary, the predisposed, and the gullible are apt to be fooled by their illegitimate appeals.  Many of them were identified by medieval and renaissance logicians, some of whose Latin names for them have passed into common use.  It’s worthwhile to consider the structure, offer an example, and point out the invalidity of each of them in turn. [i]

I have previously talked here at the Mordi Skeptics about three fallacies of relevance:

  • Appeal to Popularity (argumentum ad popularum)
  • Appeal to Authority (argumentum ad verecundiam)
  • Argument from Personal Abuse (argumentum ad hominem)

I would now like to briefly talk about three more fallacies of relevance:

Appeal to Pity (argumentum ad misericordiam)

An Appeal to Pity tries to win acceptance by pointing out the unfortunate consequences that will otherwise fall upon the speaker and others, for whom we would then feel sorry.

P1: I am a single parent, solely responsible for the financial support of my children.

P2: If you give me this traffic ticket, I will lose my licence and be unable to drive to work.

P3: If I cannot work, my children and I will become homeless and may starve to death.

C: Therefore, you should not give me this traffic ticket.

The conclusion may be false (that is, perhaps I should be given the ticket) even if the premises are all true, so the argument is fallacious.

Appeal to Force
(argumentum ad baculum)

Turning this on its head, in the Appeal to Force, someone in a position of power threatens to bring down unfortunate consequences upon anyone who dares to disagree with a proffered proposition.  Although it is rarely developed so explicitly, a fallacy of this type might propose:

P1: If you do not agree with the Government’s position, we will cut funding for your scientific research.

P2: The Government’s position is that cattle grazing in alpine national parks reduces bushfire risk.

C: Therefore, cattle grazing in alpine national parks reduces bushfire risk.

Again, it should be clear that even if all of the premises were true, the conclusion could nevertheless be false.  Since that is possible, arguments of this form are plainly invalid.  While this might be an effective way to get you to agree (or at least to pretend to agree) with the Government’s position,[ii] it offers no grounds for believing it to be true.

Guilt by association (a type of ad hominem argument)

Guilt by Association relies upon emotively charged language to arouse feelings and prejudices that may lead an audience to accept its conclusion:

P1: As all clear-thinking residents of our fine state have already realized, opposition to cattle grazing in alpine national parks is nothing but the dangerous deluded dingo of greenie anti-farming propaganda cleverly disguised in the harmless sheep’s clothing of science.

C: Therefore, banning cattle grazing in alpine national parks is bad public policy.

The problem here is that although the flowery language of the premise might arouse strong feelings in many members of its intended audience, the widespread occurrence of those feelings has nothing to do with the truth of the conclusion.

[i] Most of the information on these pages has come from http://www.philosophypages.com/lg/e06a.htm, although I have devised some of my own examples of more local relevance.

[ii] Of course, public servants are required to implement lawful Government policy whether they agree with it or not; but scientists are supposed to provide independent scientific advice.

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Filed under Logical fallacies