Avoiding Fallacious Reasoning: Lesson 2

?”Swinburne’s cosmological argument is a serious attempt to show that God is the best explanation for the existence of the universe. However, he is a well-known theist, and this fact raises some doubts about the strength of his case” (87).|ad hominem

?”Your preaching is worthless.” “Why?” “Because you don’t practice what you preach” (Socratic Logic 81).|ad hominem

Appeal to Popularity

According to Vaughn, “appeal to popularity is arguing that a claim must be true not because it is backed by good reasons but simply because many people believe it. The idea is that, somehow, there is truth in numbers” (87).

Appeal to Popularity is also known as ad populum. Use the Latin for the exercises.

?”Of course there is a God. Everyone believes that” (87).|ad populum

?”Most people believe that Jones is guilty, so he’s guilty” (87).|ad populum

?”Capital punishment can’t be wrong; 75% of the people support it” (Socratic Logic 86).|ad populum

?”Johnson argues that our current welfare system is defective. But don’t listen to him – he’s a conservative” (86).|ad hominem

?”I’m not orator, as Brutus is; but as you know me all, a plain blunt man”(qtd. in Socratic Logic 85)|ad populum

Appeal to Tradition

According to Vaughn, “Appeal to tradition is actually a kind of appeal to popularity. It is arguing that merely because a claim is sanctioned by tradition, it must be true. This kind of argument says, in effect, that a statement is true because it has been held(or approved of) for a long time” (88).

?”Ancient shaman medicine works. Native Americans have used it for hundreds of years” (88).|appeal to tradition

“Appeal to tradition is fallacious because the longevity of a traditional claim is logically irrelevant to its truth” (88).

Because a traditional claim is irrelevant to its truth, dismissing or affirming a claim because of its traditional status is fallacious reasoning. A traditional claim could very well be founded in good reasoning.

?”Of course there’s a God. Everyone believes that” (87).|ad populum

?Of course there’s a God. Everyone since the dawn of time has believed that|appeal to tradition


According to Vaughn, “the fallacy of equivocation is assigning two different meanings to the same significant word in an argument. The word is used in one sense in a premise and in a different sense in another place in the argument. The switch in meaning can deceive the reader and disrupt the argument, rendering it invalid or weaker that it would be otherwise” (89).

?”Only a man is rational. No woman is a man. Therefore, no woman is rational” (89).|Equivocation

?”The English don’t drive on the right side of the road. Therefore they drive on the wrong side” (Socratic Logic 73).|Equivocation

?”What is the highest form of animal life? The giraffe” (Socratic Logic 73) |Equivocation

?”Judge: You have just been convicted of petty larceny. Prisoner: Your honor, I just looked up your salary; you get $200,000 a year. If I’m a thief, you’re the bigger one.” (Socratic Logic 81).|Ad hominem

Appeal to Ignorance

The Latin for appeal to ignorance is ad ignorantiam

According to Vaughn, the appeal to ignorance is when the fallacy “tries to prove something by appealing to what we don’t know. Appeal to ignorance is arguing either that (1) a claim is true because it hasn’t been proven false or (2) a claim is false because it hasn’t been proven true”(90).

?”He can’t prove he earned that money, so he must have stolen it” (Socratic Logic 86).|Ad ignorantiam

?”Aristotle? Never heard of him. So he can’t be important” (Socratic Logic 86)|Ad ignorantiam

?”Super Green Algae can cure cancer. No scientific study has ever shown that it does not work” (90).|Ad ignorantiam

?100 million Americans can’t be wrong|Ad populum

?”What do you know? You’re only a teenager” (Socratic Logic 82).|Ad hominem

?”’Oh, I am very fond of children,’ said the Giant to Jack” (Socratic Logic 73).|Equivocation

?”There is no evidence that people on welfare are hardworking and responsible. Therefore, they are not hardworking and responsible” (90).|Ad ignorantiam

Vaughn adds that no one can “search all space and time” to prove that unicorns and centaurs exist. You can’t prove universal negatives.

?You can’t prove that a flying spaghetti monster doesn’t exist. Therefore, you can’t say that a flying spaghetti monster doesn’t exist.|Ad ignorantiam

False Dilemma

Here’s what Vaughn says about false dilemmas:

“In a dilemma, you are forced to choose between two unattractive possibilities. The fallacy of the false dilemma is arguing erroneously that since there are only two alternatives to choose from, and one of them is unacceptable, the other one must be true” (91).

The real world usually doesn’t operate in simple either/or premises.

?”Either we must spend billions of dollars to increase military and law enforcement operations against drug cartels, or we must legalize all drugs. We obviously are not going to legalize all drugs, so we have to spend billions on anti-cartel operations” (91).|False dilemma

Begging the Question

Vaughn on begging the question:

“The fallacy of begging the question is trying to prove a conclusion by using that very same conclusion as support. It is arguing in a circle. This way of trying to prove something says, in effect, ‘X is true because X is true’”(91).

?”The Bible says that God exists. The Bible is true because God wrote it. Therefore, God exists” (92).|Begging the Question

Put simply by Kreeft, “Begging the question means assuming what you set out to prove.

?”The accused will be given a fair trial before he is hanged” (Socratic Logic 94).|Begging the Question

?”You can’t help believing in free will; you’re predestined to think that way” (Socratic Logic 95).|Begging the Question

?Everyone is doing it|ad populum

?”All citizens have the right to a fair trial because those whom the state is obliged to protect and give consideration are automatically due judicial criminal proceedings that are equitable by any reasonable standard” (92).|Begging the Question

According to Vaughn, the above example simply states, “All citizens have the right to a fair trial because all citizens have the right to a fair trial.” Yes, it’s written in more complicated language, but it still says the same thing.

?”Senator McCarthy when he was asked for evidence to back up his accusation that a certain person was a Communist: I do not have much information on this except the general statement of the agency that there is nothing in the files to disprove his Communist connections” (A Rulebook for Arguments 74).|ad ignorantiam

Hasty Generalization

Vaughn on hasty generalizations:

“The fallacy of hasty generalization is drawing a conclusion about a whole group, or class, of things based on an inadequate sample of the group”(92).

?”All three of the college professors I’ve met in my lifetime were bald. Therefore, all college professors are bald”(92).|hasty generalization

?Don’t like your job? Then either quit or shut up|false dilemma

?”Modern philosophers are all atheists. Look at Machiavelli and Hobbes and Hume and Mill and Russel and Marx and Nietzsche and Sartre” (Socratic Logic).|hasty generalization

Slippery Slope

Vaughn on slippery slope fallacies:

“The fallacy of slippery slope…is arguing erroneiously that a particular action should not be taken because it will lead inevitably to other actions resulting in some dire outcome. A slippery slope scenario becomes fallacious when there is no reason to believe that the chain of events predicted will ever happen”(93).

?”This trend toward gay marriage must be stopped. If gay marriage is permitted, then traditional marriage between a man and a woman will be debased and devalued, which will lead to an increase in divorces. And higher divorce rates can only harm our children”(93).|slippery slope

?America: Love it or leave it|false dilemma


Vaughn on the fallacy of composition:

“The fallacy of composition is arguing erroneously that what can be said of the parts can also be said of the whole”(94).

?”Each piece of wood that makes up this house is lightweight. Therefore, the whole house is lightweight”(94).|Composition

Vaughn adds a caveat: “Just remember, sometimes the whole does have the same properties as the parts. If each part of the rocket is made of steel, the whole rocket is made of steel”(94).

?”Texas has more millionaires than any other state, therefore Texas is the richest state”(Socratic Logic 88).|Composition

?Zeno says, ”An arrow that appears to be in flight must really be at rest, for when a thing occupies a space equal to itself, it is at rest. Since the arrow never occupies a space greater or smaller than itself, it is always at rest. Since the arrow is at rest at each moment of flight, it can never move” (qtd. in Socratic Logic 88).|Composition

?”All swans we’ve ever seen were white, so all swans must be white (there are black swans around)” (Socratic Logic 100).|hasty generalization

Now for the 13th fallacy!


Vaughn on the fallacy of division:

“If you turn the fallacy of composition upside down, you get the fallacy of division – arguing erroneously that what can be said of the whole can be said of the parts” (94).

?”The house is heavy. Therefore, every part of the house is heavy”(94).|division

?”The montly payments on this car is low. Hence, the cost of the car is low”(94).|composition

?”Each soldier in the platoon is proficient. Therefore the platoon as a whole is proficient”(94).|composition

?”Irishmen are scattered all over the world. Pat is an Irishman. Therefore Pat is scattered all over the world” (Socratic Logic 88).|division

?”Everyone of the actors in this movie is great, so it must be a great movie” (Socratic Logic 88).|composition

?”Muslims are moving to France. He is a Muslim. Therefore he must be moving to France”(Socratic Logic 89).|division

?”He’ll make a good president; he comes from a good family” (Socratic Logic 89).|division

?”We went to three ball games this year and the home team lost each one. There’re losers” (Socratic Logic 100).|hasty generalization

Okay, so all 13 material fallacies have been covered from Vaughn’s chapter 5. In the next lesson the formal fallacies from chapter 2 will be covered; and in addition, lots of review on the 13 material fallacies.

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