Evaluation of Arguments by Analogy

To analyze an argument by analogy, the main task is to find the common property S that functions as a middle term in the deductive step.

To evaluate the argument, the main task is to evaluate the inductive step. You can see from the general form that the deductive step will always be valid (the syllogisms will be either AAA-1 or EAE-1, both of which are valid). But the generalization that all or no Ss are P may or may not be based on solid inductive evidence.


Comprehension Questions

1 Identify the two items being compared in the analogy given below.

Home schooling is like totalitarianism. In a totalitarian state, the rulers attempt to control all the information that others can access. Parents who home school their children do the same. Thus, just as totalitarianism is wrong, so is home schooling.

a) rulers of totalitarian governments and parents who home school
b) controlling access to information and parents who home school
c) home schooling and totalitarianism
d) totalitarian rulers and school authorities
2 Identify the respect in which these two items are similar.

Home schooling is like totalitarianism. In a totalitarian state, the rulers attempt to control all the information that others can access. Parent who home school their children do the same. Thus, just as totalitarianism is wrong, so is home schooling.

a) both attempt to control all the information that others can access
b) both are wrong
c) both are controlled by authority figures
d) both harm those whose access to information they control
3 What is the instance that is being used as the basis for the generalization?

Home schooling is like totalitarianism. In a totalitarian state, the rulers attempt to control all the information that others can access. Parent who home school their children do the same. Thus, just as totalitarianism is wrong, so is home schooling.

a) home schooling attempts to control all the information that others can access, and it is wrong
b) totalitarian governments attempt to control all the information that others can access, and it is wrong
c) parents abuse their authority, and that is wrong
d) rulers of totalitarian countries abuse their authority, and that is wrong
4 What is the generalization upon which this analogy relies?

Home schooling is like totalitarianism. In a totalitarian state, the rulers attempt to control all the information that others can access. Parent who home school their children do the same. Thus, just as totalitarianism is wrong, so is home schooling.

a) All totalitarianism is wrong
b) All home schooling is wrong
c) All attempts at controlling all the information that others can access is wrong
d) All attempts at modeling parental control on totalitarian practices is wrong
5 Which of the following is the deductive part of the argument by analogy?

Home schooling is like totalitarianism. In a totalitarian state, the rulers attempt to control all the information that others can access. Parents who home school their children do the same. Thus, just as totalitarianism is wrong, so is home schooling.

a) Any attempt to control all the information that others can access is wrong. Totalitarianism attempts to control all the information that others can access. Thus, totalitarianism is wrong.
b) Any attempt by parents to use totalitarian tactics is wrong. Parents who home school their children use totalitarian tactics. Therefore, parents who home school their children are wrong.
c) All home schooling attempts to control all the information that others can access. All home schooling is wrong. Therefore, all attempts to control all the information that others can access is wrong.
d) Any attempt to control all the information that others can access is wrong. Home schooling attempts to control all the information that others can access. Thus, home schooling is wrong.
6 Identify the two items being compared in the analogy given below.

The relation between an enzyme and its substrate is like the relationship between a lock and a key. Just as each key acts only upon a specific lock, so each enzyme acts only upon a specific substrate. Thus, no enzyme is an all-purpose tool.

a) a lock and a key is being compared with an enzyme and a substrate
b) the relationships between a lock and a key is being compared with the relationship between an enzyme and its substrate
c) all-purpose tools are being compared with specialized tools
d) specialized tools is being compared with an enzyme
7 Identify the respect in which these two items are similar.

The relation between an enzyme and its substrate is like the relationship between a lock and a key. Just as each key acts only upon a specific lock, so each enzyme acts only upon a specific substrate. Thus, no enzyme is an all-purpose tool.

a) each acts only upon a specific object
b) each one is an all-purpose tool
c) each one is a specialized tool
d) each one is not an all-purpose tool
8 Identify the respect in which these two items are similar.

The relation between an enzyme and its substrate is like the relationship between a lock and a key. Just as each key acts only upon a specific lock, so each enzyme acts only upon a specific substrate. Thus, no enzyme is an all-purpose tool.

a) an enzyme acts only upon a specific substrate, and it is not an all-purpose tool
b) a key acts only upon a specific lock, and it is not an all-purpose tool
c) an enzyme acts only upon a specific substrate, and it is a key
d) a key acts only upon a specific lock, and it is an all-purpose tool
9 What is the instance that is being used as the basis for the generalization?

The relation between an enzyme and its substrate is like the relationship between a lock and a key. Just as each key acts only upon a specific lock, so each enzyme acts only upon a specific substrate. Thus, no enzyme is an all-purpose tool.

a) no enzyme is an all-purpose tool
b) the relation between an enzyme and its substrate is like the relationship between a lock and a key
c) substances with specific relations to other substances can function as all-purpose tools
d) no substance that only acts on another specific substance is an all-purpose tool
10 Which of the following is the deductive part of the argument by analogy?

The relation between an enzyme and its substrate is like the relationship between a lock and a key. Just as each key acts only upon a specific lock, so each enzyme acts only upon a specific substrate. Thus, no enzyme is an all-purpose tool.

a) No all-purpose tool acts only upon another specific substance. All enzymes act only upon another specific substance. Therefore, no enzyme is an all-purpose tool.
b) No key unlocks every lock. An enzyme is like a key. Therefore, no enzyme operates on every substrate.
c) No substance that only acts on another specific substance is an all-purpose tool. All enzymes only act on another specific substance. Therefore, no enzyme is an all-purpose tool.
d) No key that only acts on a specific lock is an all-purpose tool. No enzyme is an all-purpose tool. Therefore, no enzyme is a key that acts only on a specific lock.


Finding the middle term | Rules for evaluation

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