BBI 3420 BBI 3420 Critical Reading and ThinkingCritical Reading and Thinking

Critical Reading Strategies: Critical Reading Strategies: Identifying ArgumentsIdentifying Arguments

Critical thinking is primarily about the Critical thinking is primarily about the evaluation of arguments.evaluation of arguments.

Definition of an argument:Definition of an argument: 1.1. a set of statements of which it is claimed a set of statements of which it is claimed

that one of those statements (the that one of those statements (the conclusionconclusion) is supported by the others (the ) is supported by the others (the premisespremises). ).

2.2. a reason or reasons offered for or against a reason or reasons offered for or against somethingsomething

ARGUMENT = CONCLUSION (assertion)ARGUMENT = CONCLUSION (assertion)

+ +

PREMISESPREMISES

= THESIS STATEMENTS= THESIS STATEMENTS

++

SUPPORTING DETAILSSUPPORTING DETAILS

Deductive ReasoningDeductive Reasoning Deductive reasoning starts with a principle Deductive reasoning starts with a principle

or accepted fact i.e. “all dogs are mammals”, or accepted fact i.e. “all dogs are mammals”, and then tries to apply this principle to other and then tries to apply this principle to other specific pieces of information or cases.specific pieces of information or cases.

Example: Example: All dogs are mammals.All dogs are mammals.Fido is a dog.Fido is a dog.

Therefore, it is true that Therefore, it is true that Fido is a Fido is a mammalmammal

A A deductive reasoningdeductive reasoning is an argument in is an argument in which it is thought that the premises provide a which it is thought that the premises provide a guaranteeguarantee of the truth of the conclusion. of the truth of the conclusion.

In a deductive argument, the premises are In a deductive argument, the premises are supposed to be a definitive proof of the truth supposed to be a definitive proof of the truth of the claim (conclusion) i.e. if the premises of the claim (conclusion) i.e. if the premises are true, it would be are true, it would be impossibleimpossible for the for the conclusion to be false. conclusion to be false.

1. All men are mortal. (premise)1. All men are mortal. (premise)2. Socrates was a man. (premise)2. Socrates was a man. (premise)3. Socrates was mortal. (conclusion)3. Socrates was mortal. (conclusion)

Deductive reasoning leads to non-Deductive reasoning leads to non-negotiable conclusion. negotiable conclusion.

The goal is not to generate new The goal is not to generate new information.information.

Some dictionaries define "deduction" as Some dictionaries define "deduction" as reasoning from the general to specificreasoning from the general to specific

Inductive ReasoningInductive Reasoning

An An inductiveinductive argument is one in which the argument is one in which the premises are supposed to support the premises are supposed to support the conclusion in such a way that if the premises are conclusion in such a way that if the premises are true, it is true, it is improbableimprobable that the conclusion would that the conclusion would be false. Thus, the conclusion follows be false. Thus, the conclusion follows probablyprobably from the premises and inferences. Here is an from the premises and inferences. Here is an example: example:

1. Socrates was Greek. (premise)1. Socrates was Greek. (premise)2. Most Greeks eat fish. (premise)2. Most Greeks eat fish. (premise)3. Socrates ate fish. (conclusion) 3. Socrates ate fish. (conclusion)

Inductive reasoning begins with several Inductive reasoning begins with several pieces pieces information, several observations, information, several observations, or examples and tries to arrive at a or examples and tries to arrive at a general pattern, tendency, or trend general pattern, tendency, or trend (hypothesis).(hypothesis).

There is always the hope that by There is always the hope that by discovering what is true for some discovering what is true for some members of a group, you will discover members of a group, you will discover what is true for all members, but there is what is true for all members, but there is no guarantee.no guarantee.

Inductive reasoning is often perceived as discovery Inductive reasoning is often perceived as discovery learning.learning.

Examples:Examples:

The members of the Williams family are The members of the Williams family are Susan, Nathan and Alexander. Susan, Nathan and Alexander.Susan wears glasses.Susan wears glasses.Nathan wears glasses.Nathan wears glasses.Alexander wears glasses.Alexander wears glasses.Therefore, Therefore, allall members of the Williams members of the Williams family wear glasses. family wear glasses.

Identifying the conclusionIdentifying the conclusion

An argument's conclusion is what the person An argument's conclusion is what the person making the argument is ultimately trying to making the argument is ultimately trying to convince you of, i.e., the person's point. convince you of, i.e., the person's point.

To try to identify the conclusion of an argument To try to identify the conclusion of an argument ask yourself 'what does the person making the ask yourself 'what does the person making the argument want me to walk away thinking?' (Note argument want me to walk away thinking?' (Note if the answer is 'nothing', them you're not dealing if the answer is 'nothing', them you're not dealing with an argument.) with an argument.)

Some Conclusion Indicator Some Conclusion Indicator Words:Words:

To identify conclusion, it often easiest to look for conclusion indicator words, such as:

therefore, consequently, as a result, thus, therefore, consequently, as a result, thus, it follows that, so it follows that, so

Identifying the PremisesIdentifying the Premises

Every argument must also consist of at least one premise.

A premise is a statement that is meant to support the conclusion. Ideally, a premise provides a good reason for believing the conclusion.

Some Premise Indicator Words:Some Premise Indicator Words:

To identify premises, it often easiest to look for premise indicator words, words that are often used to introduce a claim as a premise such as: because, since, as, for, given that

Missing Premises and Missing Premises and Conclusions:Conclusions:

When trying to figure out what the premises and conclusion When trying to figure out what the premises and conclusion of an argument are, we need to ask ourselves what the of an argument are, we need to ask ourselves what the person's point is. person's point is.

But remember that people don't always come out and say But remember that people don't always come out and say what their point is. Similarly people may not always what their point is. Similarly people may not always explicitly mention all the premises they are working with. explicitly mention all the premises they are working with.

As a result, we must be prepared to identify both missing As a result, we must be prepared to identify both missing premises and missing conclusions (i.e., conclusions or premises and missing conclusions (i.e., conclusions or premises that are not explicitly stated by the arguer, but premises that are not explicitly stated by the arguer, but that are implicit in what the arguer does say). that are implicit in what the arguer does say).

Another way to identify Another way to identify components of arguments:components of arguments:

Every conclusion must be a proposition. Every premise must be a proposition. As such, every argument must contain 2 or more propositions.

My cat has fleas.My cat has fleas.

Obama will win the next election.Obama will win the next election.

Propositions are the building blocks of arguments. A proposition is any phrase that can be true or false. The first step in analyzing the components of an argument is to identify the propositions.

Finding Propositions

Every proposition will contain a predicate (a verb phrase). As such, the best way to identify a passage’s propositions is to look for the verbs.

For example: “Athletes are not good role models. They

often behave poorly and many do not complete their education. Therefore they should not be paid as much as they are.”

The propositions of the previous passage:

1. Athletes are not good role models

2. They often behave poorly

3. The do not complete their education

4. They should not be paid as much

To determine whether or not two or more of the propositions on your list are related as premise to conclusion (and thus form an argument) plug the propositions into the blanks on the following test:

Conclusion/Premise tester:

___________________because ___________

The first place is the conclusion slot and the second place is the premise slot:

Conclusion because Premise

Example:

They should not be paid as much because athletes are not good role models