Thursday, 23 April 2015

Logical Fallacies

Here is an excerpt from my free e-book:

A logical fallacy (or ‘non-sequitur’) is an argument that may seem on the surface to support a certain view, but that does not actually support it. The Latin term, ‘non-sequitur’ means ‘it does not follow’ – the conclusion reached does not follow logically from the argument given (even though it might seem to). Using a logical fallacy does not always mean that the conclusion is wrong (although it often is), it just means that the argument, reasoning, or evidence used to reach the conclusion is not logically valid, and it is therefore impossible to have confidence in the conclusion (unless you can come up with a better argument to support it).

Critical thinking does not mean finding fault with everything. It means learning how to identify and avoid logical fallacies and evaluate the evidence for a claim objectively and rationally. There are lots of logical fallacies, and it is VERY easy to accidentally fall into the trap of using them to formulate or support our beliefs. If someone warns you against critical thinking, that should set off alarm bells! Here are some examples of common logical fallacies:

False Dichotomy

This is where someone makes an either/or statement despite the fact that there may be other options. If someone says “if you are not for us, you are against us”, that is a false dichotomy, since it is possible to be neither for nor against them.

Argument from Ignorance

Where a statement is asserted as true simply because it has not been proven false, or because the person making the assertion cannot think of any other explanation (a closely related one is the ‘argument from silence’ where the claim is asserted as true because nobody has offered any counter-argument).

Ad Hominem

This fallacy is very commonly used – where an argument is countered by attacking or questioning the person making a claim rather than addressing the argument itself.

Begging the Question, or Circular Reasoning

This is where a particular conclusion is assumed to be true when raising a question, or where the premises of an argument are dependent on the conclusion being true, and therefore, whilst possibly logical, do not actually support the conclusion. Here is a classic example of circular reasoning, from the Watchtower publication “The Bible – God’s Word or Man’s?” (chapter 6, page 86, paragraph 34):

Thus, the fact that the Bible tells of miracles is no reason to doubt its truthfulness. Rather, the fact that miracles did happen in Bible times is a powerful proof that the Bible really is the Word of God.

Here, the conclusion is that the Bible is trustworthy and authored by God. The evidence to support that conclusion is that it tells us that miracles happened, and miracles can only be performed by God. But this evidence is entirely dependent on the Bible having been written by God, and being trustworthy – which is the conclusion. Whilst perhaps internally logical, the argument is circular and therefore completely invalid.

Thought-stopping Clichés

These are little sayings that prevent you from having to think further about a problem or follow it to its obvious conclusion. Examples used by JWs include “Even if it isn’t the truth, it is still the best way of life”, “They’re just imperfect men” (when excusing the errors and injustices committed by those in charge), and “Wait on Jehovah” (when you can see something wrong and unscriptural is going on, but nobody is doing anything about it, or if a teaching is flawed or makes no sense – to stop you questioning further).

Shifting the Burden of Proof

Where a person says that they do not need to prove their claim is true, but that others should prove it is false. For example: “nobody can prove that fairies do not exist” is not a logical argument in favour of the existence of fairies, as the burden of proof rests with the one making the claim, not the one rejecting it.

Straw Man

Where a person misrepresents their opponent’s argument, then argues against their made-up, inaccurate version of it. Often this is done unintentionally – the perpetrator does not understand their opponent’s argument properly, so they argue against something that was not being claimed in the first place. Other times it is just easier to address a similar-sounding idea and hope that nobody notices, or that the listener accepts the inaccurate representation (the ‘straw man’) as the genuine argument.

Appeal to Authority

When a claim is made based on the comments of an authority on the subject, but the source is not a legitimate expert on the topic at hand, or their conclusions are in direct opposition to other expert consensus. Here is an example from the Awake! magazine of 22nd May 1994, page 21:

Scientist Francis Hitching in his book The Neck of the Giraffe writes: “When you look for links between major groups of animals, they simply aren’t there.”

Francis Hitching is a British author, journalist and film-maker. He is also a parapsychologist and a dowser – not a scientist by any definition of the word, and his conclusions on the matter of evolution are certainly in direct opposition to other expert consensus.

Argumentum Verbosium

Also known as Proof by Intimidation, or Proof by Verbosity. It refers to an argument that is so complex, long-winded, full of jargon, or poorly presented that you are obliged to accept it, simply to avoid having to unravel the minute details. It is surprisingly easy to fall prey to this fallacy, especially if you trust the person who is making the argument (in many cases, the person making the verbose argument does not really understand the issue properly themselves).

Post hoc (ergo propter hoc)

Where one event follows from another event, and the assumption is made that the first event was the cause of the second simply because it preceded it. The Latin term literally means “after this, therefore because of this”. For example, if someone does a dance and then it rains, to assume that their dance caused the rain would be a post hoc fallacy. This fallacy is very commonly used in all manner of superstitions (including prayer).

Argument from Personal Incredulity

Where a person denies or rejects an argument simply because they cannot accept or understand how it could be true. For example, if someone claims that the ancient Egyptians must have had help from extra-terrestrials to build the pyramids simply because it seems too difficult for them to have done it themselves. Another example would be if a person leaves the JWs, and a JW then claims that the person “knows it’s the truth”, even if the person who leaves really does not believe it any more.

No true Scotsman

Where the definition of a word, phrase, or concept is made unreasonably narrow, in order to exclude evidence that contradicts the argument. The typical example of this is where a person makes the claim that “no Scotsman puts sugar on his porridge”. When presented with evidence that some Scottish men do indeed put sugar on their porridge, the claim is adjusted to “no true Scotsman puts sugar on his porridge”. The definition of a Scotsman is thereby illegitimately narrowed down so as to exclude all those Scotsmen who prove the claim wrong. JWs use this fallacy to support their doctrine of the 144,000 (which is covered in the book).

Special Pleading

Where a person claims, but does not adequately demonstrate, that their argument is a special case and does not need to comply with previously set criteria or rules of logic. For example, if someone claims that the Bible is the ultimate and only authority on morality, but does not agree that human slavery is morally acceptable, they are using special pleading to break their own rule.

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