No True Scotsman Fallacy
Fallacy of Ambiguity, Fallacy of Presumption
This is actually a combination of several fallacies, but since it rests ultimately on shifting the meaning of terms a form of equivocation and begging the question, it receives special attention.
The name No True Scotsman comes from an odd example involving Scotsmen:
- 1. Suppose I assert that no Scotsman puts sugar on his porridge. You counter this by pointing out that your friend Angus likes sugar with his porridge. I then say Ah, yes, but no true Scotsman puts sugar on his porridge.
Obviously the original assertion about Scotsmen has been challenged quite well, but in attempting to shore it up the speaker uses an ad hoc change combined with a shifted meaning of the words from the original.
Examples and Discussion
How this fallacy can be used is perhaps easier to see in this example from Anthony Flews book Thinking about Thinking or do I sincerely want to be right?:
- 2. Imagine Hamish McDonald, a Scotsman, sitting down with his Press and Journal and seeing an article about how the Brighton Sex Maniac Strikes Again. Hamish is shocked and declares that No Scotsman would do such a thing. The next day he sits down to read his Press and Journal again and this time finds an article about an Aberdeen man whose brutal actions make the Brighton sex maniac seem almost gentlemanly. This fact shows that Hamish was wrong in his opinion but is he going to admit this? Not likely. This time he says, No true Scotsman would do such a thing.
You can change this to any other bad act and any group you like to get a similar argument and youll get an argument which has probably been used at some point. A common one which is often heard when a religion or religious group is criticized is:
- 3. Our religion teaches people to be kind and peaceful and loving. Anyone who does evil acts certainly isnt acting in a loving manner, therefore they cant really be a true member of our religion, no matter what they say.
But of course, the exact same argument can be made for any group a political party, a philosophical position, etc. Here is a real life example of how this fallacy can be used:
- 4. Another good example is abortion, our government has such a small Christian influence that the courts have ruled its ok to kill babies now. Typical. The people who support legalized abortion but claim to be Christians dont really follow Jesus they have lost their way.
In an effort to argue that abortion is wrong, it is assumed that Christianity is inherently and automatifcally opposed to abortion (begging the question). In order to do this, it is further argued that no one who supports legalized abortion for any reason can really be a Christian (equivocation through an ad hoc redefinition of the term Christian).
Similar arguments are made regarding a host of controversial political, social and economic questions: real Christians cant be for (or against) capital punishment, real Christians cant be for (or against) socialism, real Christians cant be for (or against) drug legalization, etc. We even see it with atheists: real atheists cant have irrational beliefs, real atheists cannot believe in anything supernatural, etc.