“Mr. Willie’s desk is always a mess because he is incompetent. A messy desk indicates a confused mind, which can only mean one thing: he is unfit for his job.” This sentence is actually very simple: “Incompetent, therefore the desk is messy; because the desk is messy, therefore he cannot be fit for his job.” · Counter-argument When we conclude that something is true simply because it “has not been proven false,” or conclude that it is false simply because it “has not been proven true,” our judgment contains a logical flaw. For example, although no one has found evidence of Atlantis’s existence yet, this does not mean that Atlantis does not exist.
Hasty Generalization When we rush to draw a conclusion based only on a small sample, we are likely to commit the fallacy of hasty generalization. “I have been to Phoenix three times, and it rained every time, so Phoenix must be a rainy city.” (In fact, Phoenix is a dry climate city.)
“Because none of the company’s interns have complained that the salary is too low, we can confidently say that the interns are satisfied with their salaries.” · Personal Preference When we judge something based solely on personal emotions without considering the actual circumstances, we are committing the fallacy of personal preference. “How can you consult Sheila about marriage problems? Don’t you know she once went to jail because of email fraud?”
· Poisoning the Well When we judge a person’s statements too heavily based on their background, especially nationality, race, or gender, our logic becomes flawed. “How can your words be taken seriously? You are from Sydney, so of course you would say Sydney is better than Melbourne.”
· You’re No Better Off
If we refuse to accept someone’s viewpoint simply because they have made the same mistake as us, our logic is also flawed. Father: “Son, you shouldn’t drink. Drinking harms the liver; how can you be drunk all the time?” Son: “Dad, aren’t you holding a glass of wine right now?” Although the son’s father is also drinking, this does not prove that his advice to his son is wrong.
· Red Herring
When we try to evade our weaknesses by changing the subject during a conversation, we are committing the “Red Herring” fallacy. (Boss to subordinate): “Don’t tell me the salary is too low. When I was your age, I only earned $100 a week.” The fact that “the boss earned little when young” is irrelevant to the current conversation, because the boss’s low salary when young does not mean the subordinate shouldn’t get a raise.
Forcing an Irrelevant Goal or Function When we reject a rule or plan because it cannot satisfy an irrelevant goal, we are committing this logical error. Pete: “Do you really think studying logic can solve the problems of this world?” Tiffany: “Probably not.” Pete: “Then why are we wasting time studying it?” · Wishful Thinking When we assume something is true (or false) simply because we strongly wish it to be so, we are committing the “Wishful Thinking” fallacy. “No matter how our team performed before, this time we will defeat the reigning champion in the first round. Our players are very confident and are putting in all their effort to achieve a great victory.”
· Appeal to Tradition When we try to convince an opponent based on factors like seniority or tradition, rather than on facts or evidence, we are committing this logical error. “Tim, don’t take the idea of going to Annapolis too seriously! Your family—including your father, brothers, grandfather, uncle, etc.—have always been in the military, and they will continue to be in the service. So, young man, your future is at West Point!” · Appeal to Popular Opinion When we accept or support a viewpoint simply because everyone agrees with it, we are committing this logical error. “I am going to vote in favor of the tax law amendment. According to the results of a recent public opinion poll, more than two-thirds of registered voters under the age of 25 support the amendment.” · Appeal to Pity What is called “appealing to pity” is the method of persuading someone by utilizing their sympathy, rather than factual evidence. (Sheila to John): “You must donate to the orphanage. These children are born without knowing who their biological parents are, let alone having a secure life.”