1

Logical Thought Fall 2004 Homework 10

Identify the fallacies of clarity (equivocation, amphiboly, fallacy of division, fallacy of composition) in the following passages:

1. All that glitters is not gold. Gold glitters. So, gold is not gold.

Amphiboly. It is ambiguous whether ‘not’ applies to ‘gold’ or to ‘all that glitters’ (the appropriate interpretation is the latter: Not all that glitters is gold.).

2. India’s citizens are mostly poor. Therefore, India is a poor country.

Composition. The author infers from the fact the parts are poor to the conclusion the whole country is poor.

3. Food is necessary to life. Sauerkraut is food. So, sauerkraut is necessary to life.

Equivocation. In the first sentence, ‘food’ is being used in the sense of ‘nourishment in general,’ while in the second sentence it is being used in the sense of ‘type of nourishment’. See below for more discussion on this example.

Fallacy of Division. The argument is parallel in structure to the following example (from class): (1) Passengers on airline X fly millions of miles each year. (2) Jenny is a passenger on airline X. (3) Therefore, Jenny flies millions of miles each way.

So…what conclusion do we draw from this observation? See below!

4. Humans are the only animals that do mathematics. Brenda is human. So Brenda is the only animal that does mathematics.

Amphiboly. It is ambiguous whether ‘only’ applies to ‘humans’ or to ‘animals that do mathematics’. In other words, the correct interpretation of the first premise is ‘Only humans are animals that do mathematics’, but the author treats ‘only’ as part of the predicate ‘animals that do mathematics’. In other words, the author interprets the first sentence as ‘All humans are the only animals that do mathematics’, giving an argument with the following structure:

(1) All humans are the only animals that do mathematics. [All M are P] (2) All people who are Brenda are humans. [All S are M] (3) Therefore, all people who are Brenda are the only animals that do mathematics. [All S are P].

This would work, except for the fact that it relies on the amphiboly in the first sentence.

Fallacy of Division. This is also a fallacy of division. In particular, it is a fallacy of 2

division that occurs because of an amphiboly.

5. The company has performed badly this year. We can only conclude that the employees have performed badly this year.

Division. The author infers from the fact that a whole has the property of performing badly to the conclusion that each part of the company has that property.

Note that one might argue that a company is nothing more than a group of people arranged under a label, i.e., that there is nothing to being a company over and above its constituent employees. In this case, for a company to perform badly is just for its employees to do badly. However, it nonetheless is possible on this understanding of the nature of a company that the company could do badly as the result of the actions of a single employee – a Kenneth Lay sort of figure, for example – despite the rest of the employees performing well. In this case it would still be a mistake to infer from the fact that the company as a whole performed badly to the conclusion that each of its employees performed badly.

Each of the following passages can be interpreted as committing an informal fallacy. For each passage, identify the fallacy committed.

6. The following is an exchange from a 2000 presidential debate:

Al Gore: I believe there are 1.4 million children in Texas who do not have health insurance. 600,000 of whom…were actually eligible for it, but they couldn’t sign up for it because of the barriers that they had to surmount.

Jim Lehrer (Moderator): Let’s let the governor respond to that…Are those numbers correct? Are his charges correct?

George W. Bush: If he’s trying to allege that I’m a hard-hearted person and I don’t care about children, he’s absolutely wrong. We spent $4.7 billion a year in the state of Texas for uninsured people and they get health care…somehow the allegation that we don’t care and we’re going to give money for this interest or that interest and not for children in the state of Texas is totally absurd. There’s only been one governor ever elected to back-to-back four-year terms, and that was me.

Red Herring. Bush doesn’t even come close to responding to Gore or answers Lehrer’s questions.

7. I need this report by Wednesday. If it isn’t ready by then, look for another job.

Appeal to Force

8. Patrick: Take a look at this article I found the other day. The author argues that, insofar as affirmative action favors the hiring of women and minorities instead of white males, affirmative action is basically a form of discrimination. 3

Stewart: Yeah – and that was written by a white male, no doubt.

Circumstantial ad hominem.

9. The legalization of drugs will not promote their use. The notion of a widespread hysteria sweeping across the nation as every man, woman, and child instantaneously becomes addicted to drugs upon their legalization is, in short, ridiculous.

Straw Man. Someone who claims that the legalization of drugs will promote their use is with all likelihood not claiming that there will be a wave of hysteria, and that every single person will become instantaneously addicted. So the author rejects as ridiculous something that really is ridiculous – but not what those who argue that the legalization of drugs would promote their use would say.

10. The war-mongering character of all this flood of propaganda in the United States is admitted even by the American press. Such provocative and slanderous aims clearly inspired today’s speech by the United States representative, consisting only of impudent slander against the Soviet Union, to answer which would beneath our dignity. The heroic epic of Stalingrad is impervious to libel. The Soviet people in the battles at Stalingrad saved the world from the fascist plague and that great victory which decided the fate of the world is remembered with recognition and gratitude by all humanity. Only men dead to all shame could try to cast aspersions on the shining memory of the heroes of that battle. – Anatole M. Baranovsky, speech to the U.N. General Assembly, 30 Nov 1953.

Given what is said in this passage, we can infer that the U.S. representative made some claims about the battle of Stalingrad (where German troops were halted in their advance into the Soviet Union during WWII) that the speaker disagrees with.

The speaker clearly appeals to the emotions of the audience, using emotionally loaded terms and phrases such as ‘heroic epic’, ‘saved the world from the fascist plague’, ‘fate of the world’, ‘shining memory’, etc.

Furthermore, the speaker commits an ad hominem abusive fallacy by suggesting that the U.S. representative is ‘dead to all shame’.

4

EXTENDED DISCUSSION ON PROBLEM 3: Why does the argument equivocate?

The argument is:

(3) (a) Food is necessary to life. (b) Sauerkraut is food. (c) So, sauerkraut is necessary to life.

We said that this argument equivocates on the meaning of ‘food’. In the first case, it means ‘nourishment in general’, while in the second it means ‘type of nourishment’.

But hold on a second. If this argument equivocates, what about the following argument?

(4) (a) Food nourishes. (b) Sauerkraut is food. (c) So sauerkraut nourishes.

Here ‘food’ in the first sentence means ‘food in general’, while it means ‘type of food’ in the second premise. But nonetheless the argument does not appear to equivocate. What’s going on?

Let’s try paraphrasing the first premise of each argument to see if we can bring out a difference in meaning of the word ‘food’. Consider the first premise of (4). Which paraphrase best captures its meaning?

(4a.1) All food nourishes. (4a.2) Some food nourishes.

It would seem that (4a.1) best captures the meaning of the first premise of argument (4).

How about argument (3)?

(3a.1) All food is necessary to life. (3a.2) Some food is necessary to life.

Well, (3a.1) seems incorrect, because it seems possible that, for example, some disease wipes out all cabbage so that it goes extinct, and consequently there is no more sauerkraut. If all food is necessary to life, then life would subsequently end, since we no longer have all food – we’re missing sauerkraut.

So the answer would seem to be (3a.2): Some food is necessary to life. But even this doesn’t seem correct! Consider a sentence with a parallel structure:

(5) Some cats are grey.

This says that, if you consider all the cats in the world, at least one of them will be grey. By parallel reasoning, does (3a.2) say, if you consider all the foods in the world, at least one of them will have the property of being necessary for life? If so, then it follows that if we were to eliminate that one type of food while leaving the others intact, life would 5

cease to be. So, does (3a.2) appear to capture the meaning of (3a)? The answer is clearly NO.

So it follows that neither (3a.1) nor (3a.2) captures the meaning of the first premise of argument (3). So ‘food’ must mean something different in the first premise of argument (3) than it means in the first premise of argument (4).

This won’t be a problem if (3) uses the same meaning in both premises. So, what can we say about the second premise of argument (3)? Again, let’s try paraphrasing:

(3b.1) All sauerkraut is food. (3b.2) Some sauerkraut is food.

Clearly, in this case (3b.1) is the intended meaning of the second premise of the argument. Likewise, the second premise of argument (4) is identical:

(4b.1) All sauerkraut is food.

So, let’s summarize our examples:

(4a.1) All food nourishes. (4b.1) All sauerkraut is food. (4c) Therefore, all sauerkraut nourishes.

(3a) Food is necessary to life. (3b.1) All sauerkraut is food. (3c) Therefore, [all? some?] sauerkraut is necessary to life.

Now we can see why (3) equivocates while (4) does not.

Argument (4) works because it uses the same meaning of ‘food’ in both of its premises. In particular, both premises refer to the class of foods. In the first premise, it is asserted that every member of the class of foods is a thing that nourishes. In the second premise, it is asserted that everything that is sauerkraut is a member of the class of foods.

Argument (3) fails because it uses different meanings of ‘food’ in each premise. In particular, the first premise does not refer to the class of foods. It is about something distinct from the class of foods, something that we might call ‘sustenance’, or ‘energy’. The second premise, like the second premise of argument (4), refers to the class of foods in that it asserts that sauerkraut is a member of that class. So, argument (3) equivocates.

I’ll leave it up to you to determine whether the ‘Jenny is a passenger’ example also equivocates, or whether it commits a fallacy of division for some other reason. If it does equivocate, then it follows that an argument can commit a fallacy of division by equivocating.