The Philosophers ToolkitFallacies in Arguments Reasoning

Questioning? Open

min

d

Clear thinking

Fallacies• A fallacy occurs when an argument

is flawed due to error in the reasoning

• Spotting faulty reasoning is an important philosophical skill

• There are many different types of fallacious arguments…

Don’t worry, there are only 8, not 38 examples

here…!

Fallacies – appeal to authority

This ad for a health drink has been ruled to be misleading for implying that it was recommended by three-quarters of doctors to the exclusion of other brands.

The Advertising Standards Authority ruled that the ads for Flora Pro-Activ cholesterol-lowering drink breached its code.

This fallacy occurs when the claim is not made by someone of authority

Fallacies – false dilema

You could buy the Mercedes, otherwise you

will have to buy the inferior Holden

The false dilema fallacy suggests if you don’t do one thing then you have to do the other when in fact there may be a range of options.

"The jawbone of an ass is just as dangerous a weapon today as in Sampson's time." --- Richard Nixon

Fallacies – post hoc fallacy

Post hoc is Latin for ‘after this’ and means that someone has given a reason to believe when there really is no reason to believe

‘Bill purchases a new PowerMac and it works fine for months. He then buys and installs a new piece of software. The next time he starts up his Mac, it freezes. Bill concludes that the software must be the cause of the freeze.’

‘The rooster crows and then the sun comes up. The rooster must have caused the sun to come up.’

Fallacy – naturalistic fallacy• The naturalistic fallacy is based on the empirically

demonstrable fact that “good” and “bad” are subjective. Harris goes to great lengths to define “good” and “bad” objectively. The problem with Harris' argument is that he is building the subjective position into the definition and claiming it to be objective.

• http://www.culturalnaturalism.org/2008/12/naturalistic-fallacy-response-to-sam.html

Fallacies – relativist fallacy

‘It might be true for you but it is not true for me…’

Witchetty grubs are tasty.

I believe in the Loch Ness Monster

The statement above becomes a fallacy when some ones beliefs of things are not true, like the existence of the Loch Ness Monster.

Fallacies – gamblers fallacy

Fallacies – affirming the conquestLatin name is modus ponens. This fallacy occurs if one knows that if A is true then B follows assumes that if B is true, A must follow.

If it's raining (A) then the streets are wet (B).

The streets are wet (B), therefore, it's raining (A).

Fallacies – genetic fallacy

This fallacy occurs when it is assumed that when something comes out of another thing it has to be similar.

Fallacies – slippery slope fallacyThis fallacy occurs when a warning is given without good grounds or justification for it being a real risk.

If you lend John $1 he will want $5 next week and before you know it

he will be owing you $100

If you do…it could open the flood gates, a can of worms,

Fallacies – Red Herring

You can’t worry about the environment when we are in

the middle of a war!

Fallacies –

Fallacies –

Fallacies –

Fallacies – ?pseudoprofundity

Self styled gurus who used carefully crafted jargon…Money doesn’t grow on trees, death comes to everyone, we all want to be loved, life is often a form of death, positive attitudinal orientations have high transferability

Aaumptions:The fallacy is also known as cum hoc ergo propter hoc (Latin for "with this, therefore because of this") and false cause. By contrast, the fallacy post hoc ergo propter hoc requires that one event occur before the other and so may be considered a type of cum hoc fallacy.

Now go ahead and complete the following and see if you can identify the type of fallacyhttp://philosophy.hku.hk/think/fallacy/ex-fallacy.php

An good description of a range of fallacies (with latin names)http://philosophy.hku.hk/think/fallacy/fallacy-list.php

A bloggers list of a huge range of fallacies.http://www.don-lindsay-archive.org/skeptic/arguments.html