Logical Fallacies by Doug McManaman

1. Logical Fallacies by Doug McManaman The Fallacy of Begging the Question: This is a common logical fallacy. It involves assuming the point that needs to be proven. In other words, in attempting to prove a point, one assumes the point that one has set out to prove. One ends up arguing in a vicious circle. Click the next slide for an example of begging the question -

2. IE, novelist John Irving writes: If you expect people to be responsible for their children, then you have to give them the right to choose whether or not to have children (abortion). With that kind of logic, one could argue anything, I.e.,: "If you expect people to be responsible for their fellow citizens, you have to give them the right to choose whether or not to pay income tax." (

3. Or, consider the following: Without the predictive precision of mathematics, any claim to truth is illusory. If you cannot express your knowledge in mathematical form, you may know something; you may have the beginnings of knowledge, but your knowledge is inevitably of a rudimentary and incomplete form. * The problem with this is that the statement is not expressed in mathematical form, nor can it be. Moreover, the author does not prove his point, but only states it.

4. Or, All rights should be enshrined in law.Abortion is a basic human right.Therefore, abortion should be enshrined in law.

5. Fallacy of Ignoring the Question:This is the fallacy that consists in proving something other than the point to be established. It consists in evading the original issue. For example, consider the following: There is an incredible amount of empty space in the universe. The distance from the sun to the nearest star is about 4.2 light years, or 25 followed by 12 noughts miles...And as to mass: the sun weighs about 2 followed by 27 noughts tons, the Milky Way weights about 160,000 times as much as the sun and is one of a collection of galaxies of which, as I said before, about 30 million are known. It is not very easy to retain a belief in one's own cosmic importance in view of such overwhelming statistics. Bertrand Russell

6. Sophistry (an instance of ignoring the question): a flawed but very deceptive method of argumentation. Consider the following debate: John: “Even the bible does not state that euthanasia is murder. It states simply: “Thou shalt not kill”. That mercy killing is murder is your inference. Bill: “John, my dictionary defines murder as the 'premeditated killing of one human being by another'.” John: “Bill, your dictionary has nothing to do with this.” * Granted, Bill’s dictionary has nothing to do with the debate, since it is probably sitting on his book shelf collecting dust. But the correct definition of words certainly is relevant to a proper debate. If John were to say “the true meaning of words has nothing to do with this”, we’d all see him for what he really is, namely irrational.

7. “The new budget will be out tomorrow. We plan to oppose the government and vote against it.” "Shouldn’t you read the document first, before you come out publicly against it?" To which the politician replied:  "There’s no virtue in delay”. * Indeed, delay and virtue seem unrelated. Virtue is a good habit, delay is an unexpected lapse of time. But it might be wise, nevertheless, to deliberately wait until all the evidence is in.

8. Or, consider the following: During a debate on sexual ethics, the person who is arguing against the Catholic understanding begins to argue, "The Pope has no business in our bedrooms. Keep the Pope out of my bedroom." Or, with regard to the abortion debate, "Keep your rosaries off my ovaries". These are forms of the fallacy of Ignoring the Question, for the Pope is not in anyone's bedroom, nor is the rosary on anyone's ovaries. The issue is whether or not the sexual act is an expression of conjugal love, or whether abortion is the destruction of a developing human life. Are these issues of privacy? One would have to show that they are. But instead of doing so, he/she employs the fallacy of Ignoring the Question and formulates excellent sophistry that is also an instance of the fallacy of Appeal to the People.

9. The Fallacy of False Cause:This fallacy consists in assuming that when one event precedes another, it is the cause of the succeeding event. “If it were permitted to reason consistently in religious matters, it is clear that we all ought to become Jews, because Jesus Christ was born a Jew, lived a Jew, and died a Jew, and because he said that he was accomplishing and fulfilling the Jewish religion.” Voltaire Or, “Look at all the wars going on in the world. They are all between different religious factions. The sooner we get rid of religion, the better off this world will be.”

10. On the road I travel to the mall in Wheaton, Md., two white men severely beat two black women Tuesday. One was doused with lighter fluid, and her attacker tried to set her afire. Both men cursed the women for being black. I couldn't help but shudder: That could have been me. This heinous act happened only hours after Pat Buchanan voters gave him 30 percent of the vote in the Maryland GOP presidential primary." — USA Today columnist and former "Inquiry" page editor Barbara Reynolds, March 6, 1992

11. The Fallacy of Accident.This fallacy consists in treating what is accidental (attribute inhering in a subject) to a subject as something essential to that subject. “No, there is only one most sacred human right, and this right is at the same time the most sacred obligation, namely, to see to it that the blood is preserved pure, so that by the preservation of the best human material a possibility is given for a more noble development of these human beings.” Hitler

12. The Fallacy of Part and Whole:This fallacy consists in attributing to a whole what belongs only to its parts (the fallacy of generalization). All Muslims are terrorists.All who with turbans and beards are terrorists.Or, the fallacy occurs when a person attributes to the part what belongs only to the whole. Ie, Since America is such a prosperous nation, all of its citizens must be well off. Here what belongs only to a whole is predicated of the parts. On Oprah recently, a so-called “expert” told a couple that they have only a 50% chance of a successful marriage. Why? Because 50% of all marriages today end in divorce. Since America is such a prosperous nation, all of its citizens must be well off.

13. Note: • It is not this fallacy that is politically incorrect. Rather, it is this fallacy as applied to certain groups of people that is politically incorrect. For example, today it is politically incorrect to apply this fallacy to: • Jews • Black people • Homosexuals • But it is politically correct to apply this fallacy to: • Americans • Conservatives • Catholics (clergy) • Muslims

14. The Fallacy of Misplaced Authority:It consists in concluding that something is true because somebody of authority said it. Yet the kind of authority he or she has and the issue at hand aresimply incongruent. "My doctor assured me that Fords are the best cars. Therefore, I'm going to buy a Ford. After all, he is a doctor.“ Or, "Albert Einstein said that criminals are not responsible for their criminal behaviour, and that such behaviour is a result of ignorance. I'd listen to Einstein over some unknown psychologist from the University of Guelph; for who has ever heard of Professor Quigglemyer?“ Or, Consulting Nobel Prize winners in Chemistry, Physics, and Medicine to comment on world issues. Or, consulting renowned scientists to comment on the existence of God.

15. The Fallacy of Ad Hominem (directed to the man): This involves the criticism of some person's position or belief by criticizing the person rather than the position itself. “Einstein couldn't have been right about Relativity, for just look at the way he combs his hair.” “Look at the way he stutters when he talks. He must not know what he's talking about, so I'm not going to vote for him.”

16. The Fallacy of the Double Standard:This fallacy consists in applying one standard for one group or individual, and another standard for an opposing group or individual. For example, according to the popular media (predominantly Democrat), Dan Quayle (a Republican) is not fit to be President of the United States because he misspelled potato (potatoe). But Bill Clinton (a Democrat) can commit perjury, adultery, and sexually abuse a woman young enough to be his daughter and lie about it under oath, and remain--in the eyes of the liberal media--a good president because “his private life has nothing to do with his public life.”

17. The Fallacy of Equivocation: This fallacy occurs when some word or expression is used with more than one meaning in an argument. For instance, consider the following argument: Addicts, who have serious emotional problems, tend to think in black and white terms, that is, they tend to be absolutists. John argues that there are absolute moral precepts. Therefore, John has serious emotional problems. Or, It is unreasonable to be so inflexible. Bill will not compromise (is inflexible) on euthanasia. Therefore, Bill is unreasonable.

18. The Fallacy of Appeal to Ignorance: This fallacy occurs whenever someone argues that a statement is false because it has not been proved to be true, or is true because it has not been proved to be false.With all the effort people have spent trying to show that people do not communicate with one another through mental telepathy, no one has succeeded in showing that telepathy does not occur. That is why we argue that communication through mental telepathy occurs.

19. Or, consider the following argument:Elephants have red eyes so that they can hide in cherry trees. Have you ever seen an elephant in a cherry tree?No.There you go! That proves my point.

20. Appeal to the People: This fallacy occurs when a speaker attempts to get some group to agree to a particular position by appealing solely to their bigotry, biases, and prejudices or, in some cases, merely to their desire to hear what they already believe. As an example, consider the last election when the politicians appealed to the people's fears about medicare and began to accuse the Alliance Party of advocating a two tiered heath care system. They were appealing to their prejudices, but they were not engaged in rational argument.

21. The Fallacy of False Analogy:This occurs when a person argues a position merely by drawing an analogy, without justifying the use of the analogy.Analogies only illustrate a point, they do not prove a point.For an example, click to the next slide:

22. Recently, an Engineer argued the following regarding the issue of abortion and the status of the fetus. He writes: The reality is that there is a gradual transition from germ cell to human being. Is a set of plans a building? Most people would say no, not until there are foundations, walls, windows, a roof, etc., something resembling a functional building. A zygote is really nothing but a set of plans. It has a set of instructions, but nothing else. It will become a genuine human only after a lot of materials are delivered and assembled properly. Not only is the above an instance of begging the question, but an analogy is employed that is radically false. A living organism is not at all like an artifact, such as a computer or a building. An organism is a unified and living whole that has an internal principle of movement. An artefact is the sum of its parts, a multiplicity of substances--not one substance--and its principle of movement is not internal, but external, namely the builders.

23. Fallacy: Appeal to Novelty • Appeal to Novelty is a fallacy that occurs when it is assumed that something is better or correct simply because it is new. This sort of "reasoning" has the following form: • X is new. • Therefore X is correct or better • Or Change is an inevitable part of life. Therefore, all change is good.

24. This sort of "reasoning" is fallacious because the novelty or newness of something does not automatically make it correct or better than something older.

25. This sort of "reasoning" is appealing for many reasons. • First, "western culture" includes a very powerful commitment to the notion that new things must be better than old things. • Second, the notion of progress (which seems to have come, in part, from the notion of evolution) implies that newer things will be superior to older things. • Third, media advertising often sends the message that newer must be better. Because of these three factors (and others) people often accept that a new thing (idea, product, concept, etc.) must be better because it is new. Hence, Novelty is a somewhat common fallacy, especially in advertising.

26. A professor is lecturing to his class. • Prof: "So you can see that a new and better morality is sweeping the nation. No longer are people with alternative lifestyles ashamed. No longer are people caught up in the outmoded moralities of the past." • Student: "Well, what about the ideas of the the great thinkers of the past? Don't they have some valid points?" • Prof: "A good question. The answer is that they had some valid points in their own, barbaric times. But those are old, moldy moralities from a time long gone. Now is a time for new moralities. Progress and all that, you know." • Student: "So would you say that the new moralities are better because they are newer?" • Prof: "Exactly. Just as the dinosaurs died off to make way for new animals, the old ideas have to give way for the new ones. And just as humans are better than dinosaurs, the new ideas are better than the old. So newer is literally better." • Student: "I see."

27. Fallacy: Appeal to Ridicule • The Appeal to Ridicule is a fallacy in which ridicule or mockery is substituted for evidence in an "argument." This line of "reasoning" has the following form: • X, which is some form of ridicule, is presented (typically directed at the claim). • Therefore claim C is false (or bad). • The fallacy of Exaggeration

28. "Sure my worthy opponent claims that we should lower tuition, but that is just laughable." • "Support the ERA? Sure, when the women start paying for the drinks! Hah! Hah!" • "Those wacky conservatives! They think a strong military is the key to peace!"

29. Remember: Moral Relativism is rooted in a denial of truth. Since one cannot reason to truth (since it does not exist), one need not obey the laws of reasoning, that is, the rules of logic. That is why in a world in which moral relativism reigns supreme (such as Canada, Western Europe, and the United States of the late 20th century), logical fallacies will be employed in order to “win the argument”. It is okay to be unreasonable, since reason is impossible anyway.