Logic: The Art of Thinking


Analysis of Arguments

Basic Questions:
Is it an argument?
What is its conclusion?
What support is offered for the conclusion?
How strong is that support?

Six Step Method for the Analysis and Evaluation of Arguments

1. Identify the argument:
-Clarify the meaning of the text
-Distinguish the argument from a disagreement, explanation, description or excuse
-Clearly indicate the main conclusion or principal thesis

2. Analyze the argument:

-Structure the premises
-Cast the argument with a diagram or schema
-Supply the missing premises / formulate the unstated assumptions
-Remove extraneous material, repetitions,digressions, illustrations,rhetorical flourishes etc...

3. Criticize the premises:

Logical criticism 

    applicability/ relevancy
      adequacy / sufficiency

Substantive criticism

probability / acceptability


4. Criticize the inferences:

Validity - soundness or unsoundness
Invalidity - degree of support

5. Introduction and Consideration of other Relevant Arguments

6. Overall Evaluation, Grading, or Final Judgment


Six Step Method:

I. Identify the Argument

Recognizing (Detecting) the Argument

Preliminary identification of conclusion and premises.
Distinguish it from an explanation or an excuse.
Distinguish it from a disagreement.
II. Analyze the Argument

1. Read argument carefully.

2. Formulate synopsis.`

3. Recast the arguments - clarify meaning - eliminate rhetoric.

4. Eliminating Rhetoric - Here are some rules of thumb that can help:

l. Look for and focus on the argument. Use contextual clues and premises and conclusion indicators as guides to the conclusion and premises.

2. Set aside phrases, sentences and even paragraphs that are extraneous to the bare argument - such items as background information, explanations, asides, repetition, elaborations, rhetorical trappings.

3. Separate each statement that belongs to the argument as a distinct premiss (or conclusion), marked with its own number tag (Pl, P2, P3, etc., and Cl, C2, etc., as necessary). This requires breaking up compound sentences so there will be just one

single point made in each set-out premise or conclusion.

4. Reformulate the premises and conclusion(s) if it is necessary in order to have all the points stated in straightforward and clear language. This especially requires transposing rhetorical questions into assertive sentences. Employ the

informative use of language alone.

5. Double check to make sure that no changes you make alter the meaning. Your restatement of the argument should not add new ideas, nor take away, nor give any new twists or shadings to the sense of the argument in the original passage.

To follow these suggestions you will usually need to do some detective work. Using the context and what is actually said in the passage as your clues, you will have to deduce from them what is actually meant.

5. Supply Missing Premises.

Missing Premises - By a missing premise, we mean a proposition which, though unstated in the argument, nevertheless is needed to link a stated premise with a conclusion. In looking for the missing premises, we are seeking what must be taken for granted in order to connect the stated premise with the conclusion. Intermediary premises - as is always the case when making explicit something implicit in an argument - we are obliged to pick the weakest possible candidate that will do the job. Otherwise we risk attributing to the arguer a position it does not have to accept, and thereby setting up a strawperson. Observe the principle of charity.

6. Arrange Premises in a Schema, cast the argument, employ a diagram.

7. State Conclusion(s).

Clearly, Fairly - Observe Principle of Charity.

Avoid Hedging or Strawperson.

8. Identify Vagueness - try to resolve it.

9. Identify Ambiguity - Amphiboly.

i. semantical

ii. syntactical

10. Identify equivocation - note its use in "shifting ground" and "hedging."

11. Identify overall standpoints - views adopted to place an opponent at a disadvantage;

Disinterested Mature Person

Reasonable man Radical

Voice in the Wilderness Plain person

World weary cynic Expert

Official Indignation Uplifter/Debaser

12. Recheck and Rewrite.

III. Critique of the Premises

A. 3 basic attacks on Premises ( listed in order of


1. Relevance - irrelevant reasons, appeals, etc. ...

Ignoratio Elenchi

Non Sequitur

Show that one could accept the premises and yet reject the conclusion without being inconsistent because the premises are not totally relevant

2. Sufficiency - hasty conclusions.

Show that premises are not strong enough to support conclusion.

3. Acceptability - problematic premises

False, Dubious, Questionable Statements.

Show Premises are false or misleading.

Principle I - each Premise of an Argument should be defended

unless exempt by context.

1. Any statement self-evidently true.

2. Any statement that is common knowledge

3. Arguer has a special warrant, status, or qualification to make the claim.

4. Statement defended elsewhere - reference given.

5. Arguer willing to provide defense of statement at another time.

6. Statement is offered without defense for the purpose of argument in order to show what follows from it.

Principle II - The less crucial and less controversial a premise is

the less serious the failure to defend it.

B. Be sure to check for:

1. Question Begging

2. Contradictory Premises - Inconsistency

3. False Dilemmas

4. Rhetorical Devices

Assuring Persuasive Definitions

Hedging Argumentative Performatives

Discounting Parenthetical Devices

Slanting Belittling

IV. Criticize the Inferences.

1. Determine the form of the argument.

Examine the relation of the premises to the conclusion. Could you accept the premises yet reject the conclusion? Then it is an inductive argument.

2. If the argument is neither deductive nor inductive, then the argument is unsatisfactory and does not have a form which satisfies the support relation. At this point we are justified in rejecting the conclusion of the argument on the basis of the

evidence offered. This is not to say, however that there is no satisfactory argument which might be offered for the conclusion; it is just to say that the argument we are examining is not such an argument.

3. If the argument is deductive or inductive, examine the premises to determine their truth value.

4. If there is at least one false premise, we are justified in rejecting the conclusion on the basis of the evidence offered in the premises. As in the case of the support relationship, this is not to say that there is no evidence, no true premises, which

might be offered for the conclusion; it is just to say that such evidence has not been offered in the argument we have been examining.

5. If all the premises are true and the argument is deductive (valid), we then know that the argument is sound and, moreover, will thus have a true conclusion. We are justified in accepting the conclusion on the basis of the evidence offered.

6. If the premises are true and the argument is inductive, we must go one step further and ask whether certain other conditions have been satisfied. If they have, we are justified in accepting the conclusion on the basis of the evidence offered and if not, then we are justified in rejecting the conclusion on the basis of the evidence.


--number of cases.

--positive analogy between premises and conclusion.

--negative analogy among premises.

--relevant factors.

Evaluate the overall strength of the argument. What is the probability that the conclusion would be true given that the premises are true?

V. Consider Alternative Arguments (Approaches & Considerations)

1. Counter examples and refutations

"just like arguing that...."

2. Counter dilemmas

3. Reduction Ad Absurdum

4. Alternative approaches

5. New hypotheses and theories

VI. Overall Evaluation - subjective appraisal of entire argument

Sample Standard for classroom use only!!!!!!!!!!!!

Points to consider weights (classroom use only)

Clarity of structure - 2

Clarity of expression - 2

Acceptability of premises - 1

Relevance of premises - 1

Strength (sufficiency) of evidence - 2

Consideration of alternatives - 1

Refutation of alternatives - 1



Other standards may be employed but one should have a clear expression of the standard before attempting to employ it. No argument should be accepted that employs fallacies, has false premises, is invalid and weak. What arguments should be accepted is the question for logicians. Consider as many factors as possible. Question as much as possible.





Newsday 3/26/85

Does it make sense to use a fire truck to go shopping at the neighborhood grocery store or pick up a take-out order of Chinese food? Common sense says no.

Yet Fire Commissioner Joseph Spinnato thinks it does. Last week he prohibited city fire fighters from making any shopping trips or food runs in private cars; he ordered them to use fully crewed trucks instead. The idea is to keep crews together, thereby possibly saving precious seconds if an alarm should sound while the truck is out of the firehouse. 

Spinnato's order also limits shopping trips to a fire company's primary coverage area -- in most cases within eight blocks of the firehouse. An aide says that was the commissioner's response to the recent homicide indictments of a fire fighter and a lieutenant after an accident last year in which a fire truck on a food run allegedly went through a red light and collided with a car killing its driver. The truck was three miles from its base at the time.

What, if anything, distance had to do with the accident is unclear. But if it's safer to keep trucks near the firehouse, keeping them in the firehouse should be safer still. And it would save wear and tear as well as fuel.

Supermarkets and take-out restaurants in most parts of the city offer free or low-cost delivery within Spinnato's prescribed limits for fire truck food runs. The commissioner should rethink his order and restrict the use of fire trucks solely to fighting fires.


N.Y. Daily News 3/25/85

 The BMW brouhaha in the White House has passed, as all things do -- but not very encouragingly so far. A group of White House bigwigs who were in West Germany last month used their diplomatic passports to arrange sweetheart discounts to buy some of BMW's luxury cars.

Fred Fielding, the White House lawyer, took a look at the situation and said neither Michael Deaver nor the others who got the cars did anything illegal or unethical -- but he decreed that it mustn't happen again and he's drafting new rules covering such purchases.

For BMW, it`s good public relations to have VIP's drive their cars. But what's good for BMW isn't necessarily good for America.

In fact, the deals smack of privilege for a select few. That may be routine in European government circles. It isn't in the U.S.-- and should stay that way.

The rules Fielding draws up should make that point forcefully and include stiff penalties, right up to and including dismissal, for public servants who try to use high office to lead the high life.


3. Get Tough With a Tax Amnesty

NEWSDAY March 25, 1985

More than a year ago, Massachusetts adopted a novel method of dealing with tax delinquents: It offered them three months to pay up without penalty -- and threatened to use an array of tough new enforcement tactics and penalties if they failed to do so.

This aggressive amnesty brought in about $33 million in three months, and New York tax officials promptly said they would look into a similar approach here. But for one reason or another, nothing came of the idea.

When the subject was raised not long ago with Roderick Chu, the state's tax and finance commissioner, he said Gov. Mario Cuomo had doubts about the amnesty concept and added, "The idea of being fair to tax cheats is perverse."

But Cuomo has come around to recognizing merit in a tax amnesty. He now says he would support one if the Legislature passed his proposals for tightening the laws against tax cheating.

That's precisely how an amnesty should be conducted -- hand in hand with a program to crack down on tax delinquents, who would otherwise have too little incentive to come clean with the tax collector. So Cuomo is correct in making his support for the amnesty idea contingent on passage of his proposals for stiffer penalties against tax dodging.

Among other things he wants a law requiring taxes on petroleum to be paid by the first distributor who buys it in this state. This proposal is designed to end extensive tax evasion in the oil and gasoline distribution industry; according to some estimates, that is costing the state as much as $200 million a year in lost tax revenue.

Senate Majority Leader Warren Anderson (R-Binghamtom), who favors a tax amnesty, says it could bring the state at least $75 million during the fiscal year that begins April 1.

Anderson and Assembly Speaker Stanley Fink should join Cuomo in pushing his tax crackdown program along with the amnesty idea.

Working in tandem, the two approaches could bring the state a welcome infusion of tax dollars that might otherwise never be collected.


4. Ratify the Genocide Treaty

NEWSDAY, March 28, 1985

Forty years after World War II, it's a scandal of historic proportions that an international treaty against genocide still languishes in the United States Senate.

The Reagan administration recognizes both the shame and the inhibition created by this situation: It's harder to condemn mass murder elsewhere when the Untied States can't muster enough Senate votes to ratify an agreement outlawing it. President Ronald Reagan said last September that the treaty would be useful "in our efforts to expand human freedom and fight human-rights abuse around the world."

But to this country's further embarrassment, Sen. Jesse Helms (R-N.C.) and a few other conservatives have managed once more to derail the administration's ratification effort. They've dredged up many of the old and discredited arguments that the treaty could somehow put the Untied States at the mercy of the World Court or otherwise compromise U.S. sovereignty. Nicaragua's complaint to the World Court over U.S. support for the contras is being stitched into the debate even though it's wholly irrelevant to the genocide treaty.

To appease the opposition, the administration now says it would agree to add a reservation giving the Untied States the right to exempt itself from the World Court's jurisdiction. This is a phony issue, since the treaty provides only that that world

Court shall listen to disputes over the treaty's language. Its implementation is by domestic laws that each country enacts on its own.

It might be argued that a political price must be paid for Senate passage and that limited approval of the treaty is better than none at all. But it's doubtful that one reservation will satisfy the treaty's opponents; chances are it will only open the door to more.

A president who can lobby a bad weapon like the MX missile through the House of Representatives ought to be able to push a good treaty like this one through the Senate.


back to top