Fallacies FORMAL FALLACIES Affirming the Consequent If A

Fallacies

FORMAL FALLACIES Affirming the Consequent If A then B + A Example: If you are English then you like fish and chips. You like fish and chips. ---------------So, you are English. B

2. Denying the Antecedent If A then B + Not A Not B Example: If you are English then you like fish and chips. You are not English. ------------So, you do not like fish and chips.

INFORMAL FALLACIES (Deceit) Begging the question 1 (+ ? ) … 1 Examples: 1 2 3 ‘The Bible says God exists. Everything in the Bible is true, because God wrote it. So God exists. ’ ‘Australia’s present constitution is the best guarantee of stable government because it is the constitution which best protects us from governmental instability. ’ ‘It’s wrong to murder people. Capital punishment involves murdering people. So capital punishment is wrong. ’

2. Equivocation All P are Q + All Q are R All P are R Should be All P are Q 1 + All P are R All Q 2 are R

Examples: ‘The laws of nature must have a lawmaker because they are laws, and all laws have a lawmaker. ’ ‘Nothing is better than eternal heavenly bliss; and a Big Mac™ is better than nothing. Thus a Big Mac™ is better than heaven. ’ ‘Six is an odd number of legs for a horse. Odd numbers are not divisible by two. Six is not divisible by two’

(Diversion) Straw Man Argument directed against an inaccurate statement of the opponent’s position Examples: ‘The theory of evolution states that humans are no different from apes, but humans are clearly smarter than apes, so theory of evolution is wrong. ’ ‘People who believe we should spend less on defence apparently believe that the instability in the former Soviet Union and Africa poses no threat to our interests. ’ ‘I’m in favour of legalised gambling. There are those who oppose it, but they apparently believe that anything that’s fun is sinful. ’

(Diversion) Slippery Slope fallacy An argument against a proposed action which claims that it will very probably lead to bad consequences Examples: ‘Legalised voluntary euthanasia sounds fine, but inevitably the conditions for euthanasia will be loosened. First, incurable terminal diseases will be included, then merely debilitating conditions, then expensive-to-treat illnesses, then simply inconvenient illnesses will qualify. ’ ‘First they’ll ask for guns to be registered, then they’ll want to institute a licence test, then they’ll ban certain weapons, then they’ll take them all away, and we’ll be quite defenceless. ’ ‘It’d be a mistake to try to recreate the welfare programs of the 60 s and 70 s. If you give people something, they’ll come to expect it, and then to regard it as a right. Who would then work rather than sit back and be paid. ’

(Diversion) False Dilemma A or B + not A B Examples: ‘Don’t vote for the bill requiring a deposit on bottles. There’s lots of litter other than bottles; we should require a deposit on all potential litter or on none. ’ ‘You’re either part of the solution, or part of the problem. ’ ‘Either we ban all guns or we let crime run amok. ’

(Irrelevance) Argumentum ad hominem 1(Attack on A) [A is not trustworthy] + 2[believe someone iff they are trustworthy] A says that X [don’t believe what A says] + Don’t believe that X

Examples: Abusive: ‘We have to act now to save the forests. ’ ‘You would think that, you’re a hippy. ’ Circumstantial: ‘We should develop normal relations with Cuba. ’‘You only say that because you want to make money selling their fancy cigars. ’ Tu quoque: ‘You’re telling me I should drink less? You haven’t been sober in a year!’

(Irrelevance) Genetic fallacy One attacks the causes of a belief rather than the justifications for it. Examples: ‘Studies show that passive smoking is quite harmless. ’ ‘Those studies were all commissioned and funded by cigarette companies. ’ ‘The best system of insurance includes a type of no-fault policy. ’ ‘That’s a type of insurance policy being promoted by the insurance companies themselves. I’m sure it can’t be good for their customers. ’ ‘Psychiatric hospitals arose from an attempt to control disruptive elements, not to help them. We should eliminate them. ’

(Irrelevance) Authority 1(A is an authority) [A is trustworthy] A says that X + + 2[believe what A says] Believe that X someone iff they are trustworthy

Examples: ‘Can you doubt that air has weight when you have the clear testimony of Aristotle affirming that all the elements have weight including air, and excepting only fire. ’ ‘I’m not a doctor but I play one on TV. ’ ‘A majority of doctors think that the morality of young people has declined. ’

(Irrelevance) Ignorance (Argumentum ad ignorantiam) ‘A’ is not proved + [If ‘A’ was true it would have been proved] ‘A’ is not true ‘not A’ is not proved + [If ‘A’ was false, ‘not A’ would have been proved] ‘A’ is true

Examples: ‘My wife must be having an affair since I can’t prove that she isn’t. ’ ‘Since no one has been able to prove God’s existence, God does not exist. ’ ‘Since no WMD’s have been found, there were never any WMDs. ’

(Irrelevance) Motivational Appeals Attempting to induce someone to accept a conclusion by appealing to motives rather than providing reasons to think that the conclusion is true. Examples: Force (Threat, Fear, Argumentum ad baculum): ‘You should not put smoking bans in your restaurants because if you do we smokers will boycott you, and we are a large part of your customer base. ’ Pity (Argumentum ad misericordiam): ‘I am qualified for this job – I have some expeience and I need the money to get my baby sister into the eyehospital. ’ Prejudicial (Poisoning the well): ‘Would anyone be so naïve as to doubt that the finest painters were French? ’

Miscellaneous) Sorites Claiming that two alternatives cannot be uncontroversially distinguished, and that therefore there is no difference between them. Property P 1 is defined in terms of X. Property P 2 is defined in terms of X. X can vary by small increments. A has property P 1. [For anything, B, with property P 1, if property P 1 is different from property P 2 then there is a point at which incremental variation of X from that which defines P 1 towards that which defines P 2 is sufficient to result in B having property P 2 rather than P 1. ] If A has P 1 and X is incrementally varied then A still has property P 1. Therefore, there is no point at which incremental variation of X from that which defines P 1 towards that which defines P 2 is sufficient to result in B having property P 2 rather than P 1. Therefore, P 1 and P 2 are not different.

Examples: From the moment of conception, a foetus grows and changes constantly. At each moment it differs in only the slightest way from the previous moment. What, then, is the exact point at which the foetus ceases to be a mere foetus and becomes instead a person? For any point identified as the moment when a foetus becomes a person, the foetus at that point will not differ significantly from the foetus a moment earlier. Since we can’t identify any moment at which a foetus becomes a person, and yet the child is already a person when born, the foetus must be a person from the moment of conception. All animals have rights and we ought to respect these rights. How so? Humans have rights, we all accept that. But what is the relevant difference between humans and higher apes? – say the chimpanzee? Humans and higher apes are both conscious, intelligent beings, capable of learning and communicating through language. Apes, in turn, are closely related to other higher mammals, higher mammals to lower mammals, and lower mammals to other animals. Exactly where do rights come into the picture? We cannot draw a sharp and non -arbitrary distinction between those animals whose rights we ought to acknowledge and those we needn’t bother with, so the rights of all animals ought to be respcted.

(Robert Nozick (1974), Anarchy, State, and Utopia, New York: Basic Books, pp 290 -292) 1. 2. 3. 4. 5. There is a slave completely at the mercy of his brutal master’s whims. He is often cruelly beaten, called out in the middle of the night, and so on. The master is kindlier and beats the slave only for stated infractions of his rules (not fulfilling the work quota, and so on). He gives the slave some free time. The master has a group of slaves, and he decides how things are to be allocated among them on nice grounds, taking into account their needs, merit, and so on. The master allows his slaves four days on their own and requires them to work only three days a week on his land. The rest of the time is their own. The master allowes his slaves to go off and work in the city (or anywhere they wish) for wages. He requires only that they send back to him three-sevenths of their wages. He also retains the power to recall them to the plantation if some emergency threatens his land; and to raise or lower the three-sevenths amount required to be turned over to him. He further retains the right to restrict the slaves from participating in certain dangerous activities that threaten his financial return, for example, mountain climbing, cigarette smoking.

6. 7. 8. 9. The master allows all of his 10, 000 slaves, except you, to vote, and the joint decision is made by all of them. There is open discussion, and so forth, among them, and they have the power to determine to what uses to put whatever percentage of your (and their) earnings they decide to take; what activities legitimately may be forbidden to you, and so on. Though still not having the vote, you are at liberty (and are given the right) to enter into the discussions of the 10, 000, to try to persuade them to adopt various policies and to treat you and themselves in a certain way. They then go off to vote to decide upon policies covering the vast range of their powers. In appreciation of your useful contributions to discussion, the 10, 000 allow you to vote if they are deadlocked; they commit themselves to this procedure. After the discussion you mark your vote on a slip of paper, and they go off and vote. In the eventuality that they divide evenly on some issue, 5, 000 for and 5, 000 against, they look at your ballot and count it in. This has never yet happened; they have never yet had occasion to open your ballot. (A single master also might commit himself to letting his slave decide any issue concerning him about which he, the master, was absolutely indifferent. ) They throw your vote in with theirs. If they are exactly tied your vote carries the issue. Otherwise it makes no difference to the electoral outcome. The question is: which transition from case 1 to case 9 made it no longer the tale of a slave?

(Miscellaneous) False Analogy Arguing faultily that because two things have certain similarities they will also have other similarities. An argument from analogy generally looks like this: It is claimed that the Object (an argument, or a natural phenomenon, or an idea, or what you will) has properties P 1, P 2, …, Pn. The Analogue also has properties P 1, P 2, …, Pn. The analogue has property P. Therefore the object has property P. The argument relies upon the hidden premiss that [5. If two objects share properties P 1, P 2, …, Pn, they will also share property P. ] Arguments like this are fallacious if the hidden premiss is not true or if it is not obviously true and yet is not argued for.

Examples: A country is like a ship with the president as the captain. Just as the captain should be obeyed without question during a storm, the president should be given special powers in periods of crisis. The finances of a government are like the finances of a family. A family can’t go on spending more than it earns. Spending a great deal of money to provide medical care for the aged is like wasting money on a car. When a car is all worn out, needs a new engine, transmission, and body work, it’s better just to junk it. The same goes for people.