Fallacies
What are logical fallacies?
A logical fallacy is an error of reasoning. When someone adopts a position, or tries to persuade someone else to adopt a position, based on a bad piece of reasoning, they commit a fallacy. Some logical fallacies are more common than others, and so have been named and defined. When people speak of logical fallacies they often mean to refer to this collection of well-known errors of reasoning, rather than to fallacies in the broader, more technical sense given above.
Not alla fallacies result in a wrong statement, it is the method which brought to the answer that is wrong if subject to a fallacy.
Not alla fallacies result in a wrong statement, it is the method which brought to the answer that is wrong if subject to a fallacy.
Common Fallacies
1. Personal Argument
Argumentum ad hominem
The Ad hominem fallacy can be directly translated from latin as against the man, against the person, it rappresents an attack towards a person which is totally irrelevant to the topic of the argument
Bill: "I believe that abortion is morally wrong."
Dave: "Of course you would say that, you're a priest."
Bill: "What about the arguments I gave to support my position?"
Dave: "Those don't count. Like I said, you're a priest, so you have to say that abortion is wrong. Further, you are just a lackey to the Pope, so I can't believe what you say."
2. Argument from ignorance
Argumentum ad ignorantiam
The Argumentum ad Ignorantiam fallacy confuses us in believing that something is true just because we aren't certain that it isn’t true.
3.False cause and effect
Post Hoc Ergo Propter Hoc
The Post Hoc Fallacy, also known as as False cause and questionable cause, is committed when one event (x) causes another event (y) and it is assumed that event (y) occurred because of event (x)
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.
4.Hasty Generalisation
Dicto Simpliciter
The hasty generalization fallcy, also known as Hasty induction, or fallacy of insufficient statistics, happens when a person draws a conclusion without enough information to proove it
Smith, who is from England, decides to attend graduate school at Ohio State University. He has never been to the US before. The day after he arrives, he is walking back from an orientation session and sees two white (albino) squirrels chasing each other around a tree. In his next letter home, he tells his family that American squirrels are white.
5.Circular Reasoning
Petitio Principii
The Circular Reasoning fallacy is also known as begging the question and reasoning in a circle, it is a tautology. In this type of fallacy the premises claim that the conclusion is true or assume that the conclusion is true
Bill: "God must exist."
Jill: "How do you know."
Bill: "Because the Bible says so."
Jill: "Why should I believe the Bible?"
Bill: "Because the Bible was written by God."
6.
Special Pleading
The Special Pleading fallacy occours when a person applies rules or standards to others while exempting himself from the rules, without giving a good justification for the exemption
Mike: "Barbara, you've tracked in mud again."
Barbara: "So? It's not my fault."
Mike: "Sure. I suppose it walked in on its own. You made the mess, so you clean it up."
Barbara: "Why?"
Mike: "We agreed that whoever makes a mess has to clean it up. That is fair."
Barbara: "Well, I'm going to watch TV. If you don't like the mud, then you clean it up."
Mike: "Barbara..."
Barbara: "What? I want to watch the show. I don't want to clean up the mud. Like I said, if it bothers you that much, then you should clean it up."
7.Equivocation
The Equivocation fallacy occours when ambiguous language is used to describe a certain situation
The humanity of the patient's appendix is medically undeniable.
Therefore, the appendix has a right to life and should not be surgically removed.
8. False Analogy
The False Analogy fallacy occoures when it is assumed there is a similarity between two things, when in fact the two things are not similar.
Saying that the probability of a complex organism evolving by chance is the same as a tornado ripping through a junkyard and created a 747 by chance
10. Loaded Question
A Loaded Question fallacy is a question with a false or questionable presupposition
11. Appeal to belief
The Appeal to belief Fallacy occours when a majority of people think that a claim is right, using the nember of people as evidence for the righteousness of the claim
God must exist. After all, I just saw a poll that says 85% of all Americans believe in God.
12. Straw man fallacy
The Straw Man Fallacy occourswhen a person (x) ignores a person's (y) actual position and substitutes a distorted version of position (y).
Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that.
13. Poisoning the well
The Poisoning the well fallacy happens when triying to lower the importance of what a person (x) might later claim by presenting unfavorable information (true or false) about the person (x)
Don't listen to him, he's a scoundrel
14. Slippery Slope
The Slippery Slope fallacy occours when there is no reason i believing that one event must follow from another without an argument for the claim.
You can never give anyone a break. If you do, they'll walk all over you.
15. Gambler's Fallacy
The Gambler's fallacy occours when a person assumes that something that happens in the long term can be stopped in the short term.
Bill is playing against Doug in a WWII tank battle game. Doug has had a great "streak of luck" and has been killing Bill's tanks left and right with good die rolls. Bill, who has a few tanks left, decides to risk all in a desperate attack on Doug. He is a bit worried that Doug might wipe him out, but he thinks that since Doug's luck at rolling has been great Doug must be due for some bad dice rolls. Bill launches his attack and Doug butchers his forces
16. Personal Attack
The Personal Attack fallacy is committed when evidence is substituted by negative remarks to attack a claim
when
Bill says that we should give tax breaks to companies. But he is untrustworthy, so it must be wrong to do that.
17. Appeal to authority
The appeal to authority fallacy occours the person that claims something on a subject isn't an authority to it.
Bill and Jane are arguing about the morality of abortion:Bill: "I believe that abortion is morally acceptable. After all, a woman should have a right to her own body."
Jane: "I disagree completely. Dr. Johan Skarn says that abortion is always morally wrong, regardless of the situation. He has to be right, after all, he is a respected expert in his field."
Bill: "I've never heard of Dr. Skarn. Who is he?"
Jane: "He's the guy that won the Nobel Prize in physics for his work on cold fusion."
Bill: "I see. Does he have any expertise in morality or ethics?"
Jane: "I don't know. But he's a world famous expert, so I believe him."
Fallacies in real life situations
Fallacies occour daily in various situations, here is a video to demonstrate this: