|
||||||
A second major group of fallacies is those that presume too much: the reasoning involves false or unwarranted assumptions.
Some types:
False dilemma
Reasoning that presents an either/or choice when in fact other options exist.
e.g. 'If you don't agree that the government's new childcare policy is bad then you're either heartless or childless'.
Begging the question
An circular form of reasoning which relies on a premise that would only be accepted by someone who was already convinced that the conclusion was true.
e.g. 'The Bible says that God exists, so God must exist'
Slippery slope
Reasoning that presents a chain of increasingly dire consequences as following inevitably from accepting some claim.
e.g. 'If we agree to ban violent pornography, then it won't be long before they ban X-rated films, if they do that then before you know it R-rated films will also be banned, then they'll ban any sort of reference to sex in the media, and then we'll be living in a puritanical tyranny that won't even let you kiss someone on the cheek in public! So we shouldn't agree to any ban on violent pornography'
Slippery slope isn't always a fallacy. Click here for further discussion.
Argument from ignorance
Reasoning that since something hasn't been proven false, then it must be true.
e.g. 'Since you can't prove that the tooth fairy doesn't exist, she exists'
Coincidental correlation
Reasoning that assumes that based solely on the fact that X happens after Y we can conclude that Y must cause X.
e.g. 'You hear thunder after you see lightning, so lightning must cause thunder'
Let's try a practice exercise...
Sort the white boxes according to the fallacy they present:
Drag this image onto the workspace to proceed. You must be using the inbuilt browser in Rationale 1.3 or later.
After you've finished this exercise drag this thumbnail onto the workspace to see the model answer:
This material has been developed independently of the International Baccalaureate, which in no way endorses it.
© Austhink 2013. Rationale Exercises version 0.1, Jan-13
