Logical Fallacies

Under construction, feel free to revise and comment any correction.

What are logical fallacies?

Why is important to identify them?

Organized by alphabetical order.

1. Ad hominem: Attacking the person that makes the argument rather their arguments. E.g.: “Skeptic: Homeopathy have been scientifically demonstrated not to be effective. Believer: Closed minded stupid people like you can’t see how homeopathy works.”
2. Ad ignorantiam: Arguing something can’t be true because the person can’t comprehend it. E.g.
3. Ad populum: To believe that something is true/real/works because it’s popular and many people use/do it. Because hundreds of people like to throw some Coca-cola to the gas tank to clean the motor that doesn’t make it a good practice.
4. Anecdotal evidence: ‘Information that cannot be tested scientifically’ (Skeptoid, 2007) , therefore not enough evidence for testing hypothesis. Maybe just to formulate them.
5. Argument from antiquity: “Something that old gotta work, right?” Not really, antiquity do not necessarily is proof of something functioning.
6. Argument from authority: “There’s no such thing as radioactive waste from nuclear centrals, the President said it”. What does the President know about radiation and radioactive waste? Is he a professional in nuclear technology or just a lawyer? It’s important what kind of authority made the claim.
7. Argument from final consequences: Based in a reversal of cause and effect. They argue that something was caused because of the Ultimate effect it has, or the purpose it works for. (The Skeptics Guide to the Universe)
8. Argument from personal Incredulity: It’s to say: “I can’t explain or comprehend this; therefore, it can’t be true”. Your comprehension it’s irrelevant for the existence of something.
9.  Begging the question: This question has an implicit premise that takes you directly to the conclusion. “Did you stopped hitting your husband?” By answering NO you’re admitting you hit your husband. By answering YES you admitted you hit your husband. . It’s a way of questioning that wants to trap you to answer what they want. It’s important to be aware.
10. Confusing association with causation: ‘[Similar to post-hoc] It assumes cause and effect for two variables simply because they occur together. This fallacy is often used to give a statistical correlation a causal interpretation.’ (The Skeptics Guide to the Universe) E.g. An increment of car sales and in drug users. The fallacy would be to attribute the increment in car sales to the increment in drug user, because there could be other variables like the car sales could go up simply because people have more money. It’s an obvious fallacy when no other variable is considered and discarded.
11. Confusing “unexplained at the moment” with “unexplainable”: That there’s no evidence for X phenomena doesn’t mean that it would be always inexplicable, or that it defies the laws of nature or requires a paranormal explanation.
12. False analogy: To assume a similarity between two things, persons or situations when in fact what is compared is no similar in the evoked way. “Creationist: Life is like a house. Because of the entropy the house get’s messier because the house doesn’t organize itself. Therefore, life has an intelligent being that fix it. Skeptic: Wrong. The house is an inanimate object, while life uses energy to grow and reproduce.
13. False continuum: Thinking that because there’s not a definitory demarcation line between two extremes, then the distinction between the extremes is not real or significative. E.g. There’s no clear demarcation line between drug sell at pharmacies from that sell at the streets, therefore they are the same.
14. False dichotomy: To reduce arbitrarily a group of many possibilities to just only two. E.g. Life it’s to complex for evolution, therefore it was intelligently designed.
15. False premise:
16. Genetic fallacy:
17. Inconsistent:
18. Major premise not declared:
19. Moving the goal post:
20. Non-Sequitur:
21. No true Scotsman:
22. Poisoning the well:
23. Post-hoc Ergo Propter-hoc:
24. Red Herring: An irrelevant distraction to mislead the audience from the central idea.
25. Reductio ad absurdum:
26. Selective observation:
27. Slippery hill:
28. Special Pleading:
29. Straw man:
30. Tautology:
31. The Fallacy fallacy:
32. To quoque: You too/ It’s ok to do it because someone does it. E.g. I drink battery acid because my friends do it./ It’s ok for me to steal money from my grandma because my father does the same.
33. Weasel words/ Words salad: Not exactly a logical fallacy, but used to reinforce unscientific claims. E.g. Scientists say…/ A study found…/ My mother told me…/ Quantum Mechanics clearly explain how homeopathy works…

There could be error, there could be no error, whichever it’s important to keep as clear and easy to understand as possible. If you find something hard to understand or some error, contact us.

References:

Dunning, B. (2007). A magical journey through the land of logical fallacies-part 1. Retrieved in October 20, 2013, from: http://skeptoid.com/episodes/4073

Master of logical fallacies. Retrieved in October 20, 2013, from: http://utminers.utep.edu/omwilliamson/ENGL1311/fallacies.htm

Purdue OWL. Logical fallacies. Retrieved in October 20, 2013, from: https://owl.english.purdue.edu/owl/resource/659/03/

The Skeptics Guide to the Universe. Retrieved in October 20, 2013, from: http://www.theskepticsguide.org/resources/logical-fallacies