Argument Structure. Arg.A.“All men are animals and all animals are mortal and Socrates is a man so Socrates is mortal.” with base: F.B:< ‘All men are.

Slides:



Advertisements
Similar presentations
Reason and Argument Chapter 7 (1/2).
Advertisements

The Basics of Logical Argument Two Kinds of Argument The Deductive argument: true premises guarantee a true conclusion. e.g. All men are mortal. Socrates.
Common Valid Deductive Forms: Dilemma P or q If p then r If q then s Therefore, r or s Example, Either George W. Bush will win the election or John Kerry.
1 Philosophy and Arguments. 2Outline 1 – Arguments: valid vs sound 2. Conditionals 3. Common Forms of Bad Arguments.
Logical Fallacies 8 th grade ELA. What is a logical fallacy? Definition: a mistake in reasoning. Used when trying to make an argument and the use of bad.
Moral Reasoning   What is moral reasoning? Moral reasoning is ordinary critical reasoning or critical thinking applied to moral arguments.
Refutation, Part 1: Counterexamples & Reductio Kareem Khalifa Philosophy Department Middlebury College.
Philosophy 103 Linguistics 103 Introductory Logic: Critical Thinking Fall 2007 Dr. Robert Barnard.
The Ontological Proof For around a thousand years, various proofs for the existence of God have gone by the name ‘The Ontological Proof.’ The first person.
BUS 290: Critical Thinking for Managers
Some Methods and Interests. Argument Argument is at the heart of philosophy Argument is at the heart of philosophy It is the only method for getting results.
Copyright © Zeph Grunschlag,
Clarke, R. J (2001) L951-08: 1 Critical Issues in Information Systems BUSS 951 Seminar 8 Arguments.
Logical and Rule-Based Reasoning Part I. Logical Models and Reasoning Big Question: Do people think logically?
Introduction to Philosophy Lecture 7 The argument from evil By David Kelsey.
Moral Reasoning   What is moral reasoning? Moral reasoning is ordinary critical reasoning or critical thinking applied to moral arguments.
By Ryan Davis and Nick Houska. Fallacies  Fallacies- are defects in an argument that cause an argument to be invalid, unsound or weak  Example: Hasty.
Basic Argumentation.
Logical Fallacies 8 th grade ELA. What is a logical fallacy? Definition: a mistake in reasoning. Used when trying to make an argument and the use of bad.
0 Validity & Invalidity (Exercises) December 23, 2005.
Chapter 2: Lecture Notes Pinning Down Argument Structure.
Logical Arguments. Strength 1.A useless argument is one in which the truth of the premisses has no effect at all on the truth of the conclusion. 2.A weak.
Time 2 hr No choice 1st six week course will be for the paper (including teasers) The 1st six week outlines attached in form of slides.
 Born to a noble family in Italy  As a young man, joins the Benedictine Order in Normandy, France, residing in the monastery there for 30 years – 15.
Reason: as a Way of Knowing Richard van de Lagemaat, Theory of Knowledge for the IB Diploma (Cambridge: CUP, 2005)
Introduction to Philosophy Lecture 5 The Ontological Argument By David Kelsey.
Introduction to Philosophy Lecture 3 An introduction to Deductive arguments By David Kelsey.
Argument Theory. SOCRATES: … And so come, Gorgias, imagine you are questioned by these men and by myself as well, and answer what it is you claim to be.
PARADOXES Zeno's Paradoxes One can never reach the end of a racecourse, for in order to do so one would first have to reach the halfway mark, then the.
Mike McGuire MV Community College COM 101 A Closer Look at Logos Syllogism, Enthymeme, and Logical Fallacies ENGL102 Ordover Fall 2008.
Debate: The Logical Argument. There are are three things wrong wrong with this sentence.
Chapter 3: MAKING SENSE OF ARGUMENTS
2.8 Methods of Proof PHIL 012 1/26/2001.
0 Validity & Invalidity (Exercises) All dogs have two heads. 2. All tigers are dogs. ___________________________________ 3. All tigers have two.
Fallacies To error in reason is human; to analyze divine!
DEDUCTIVE VS. INDUCTIVE REASONING. Problem Solving Logic – The science of correct reasoning. Reasoning – The drawing of inferences or conclusions from.
Today’s Topics Introduction to Proofs Rules of Inference Rules of Equivalence.
Chapter Five Conditional and Indirect Proofs. 1. Conditional Proofs A conditional proof is a proof in which we assume the truth of one of the premises.
BBI 3420 Critical Reading and Thinking Critical Reading Strategies: Identifying Arguments.
Introduction to Philosophy Lecture 5 The Ontological Argument By David Kelsey.
Argument Diagramming Part I
Do Now  What does logos appeal to in an advertisement?  Give three examples.
Use and mention Logic is part of philosophy Logic is a word “Logic” is a word Use There’s glory for you. --what do you mean by “glory”? Mention.
CHAPTER 9 CONSTRUCTING ARGUMENTS. ARGUMENTS A form of thinking in which certain reasons are offered to support conclusion Arguments are Inferences - Decide.
Philosophy and Logic The Process of Correct Reasoning.
Errors in Reasoning. Fallacies A Fallacy is “any error in reasoning that makes an argument fail to establish its conclusion.” There are two kinds of fallacies.
Doing Metaphysics: Questions, Claims, and Proofs.
Text Table of Contents #5: Evaluating the Argument.
Presumption, Ambiguity, & Illicit Transference 2/17/2016 C.G. Parker | PHIL
Do now Can you make sure that you have finished your Venn diagrams from last lesson. Can you name 5 famous mathematicians (including one that is still.
Philosophy of Religion Ontological Argument
PHIL102 SUM2014, M-F12:00-1:00, SAV 264 Instructor: Benjamin Hole
DEDUCTIVE vs. INDUCTIVE REASONING
WEEK 3 VALIDITY OF ARGUMENTS Valid argument: A deductive argument is valid if its conclusion is necessarily and logically drawn from the premises. The.
What makes a Good Argument?
Inductive / Deductive reasoning
Errors in Reasoning.
Errors in Reasoning.
Syllogism, Enthymeme, and Logical Fallacies
The Ontological Argument
Validity and Soundness
DEDUCTIVE vs. INDUCTIVE REASONING
Building Argument and Integrating Evidence
The Ontological Argument
II. Analyzing Arguments
Philosophy and Logic Section 4.3
Philosophical Methods
Validity.
Basic Errors in Logic Featured in “Love is a Fallacy” By Max Shulman
Presentation transcript:

Argument Structure

Arg.A.“All men are animals and all animals are mortal and Socrates is a man so Socrates is mortal.” with base: F.B:< ‘All men are animals’, ‘All animals are mortal’, ‘Socrates is a man’, ‘Socrates is mortal’ > break it up into smaller parts. F.1:< ‘All men are animals’, ‘All animals are mortal’, ‘All men are mortal’ > F.2:< ‘All men are mortal’ ‘Socrates is a man’, ‘Socrates is mortal’ >

< ‘United Airlines are on strike’, ‘Other airlines will carry more passengers’ > the argument was really < ‘United Airlines are on strike’, ‘United Airlines will not carry passengers’ > < ‘United Airlines will not carry passengers’, ‘The airlines as a whole have to carry so many passengers’, ‘Other airlines will carry more passengers’ >

1 A premise or conclusion that is assumed but not stated is said to be suppressed. (NB: This differs from the definition given in the Text and is that more usually adopted.) 2 An argument which is interpreted as containing suppressed premises or a suppressed conclusion is called an enthymeme — the argument is enthymematic. Explicit Claim / Argument Interpretation  Enthymematic Argument

Suppressed Premisses John is a native-born American John is an American citizen Interpretation  John is a native-born American All native-born Americans are American Citizens John is an American citizen

Suppressed Conclusion No sane person would do that but you would Interpretation  No sane person would do that (i.e. X) You would (do X) You are insane

a. Charity Try to reconstruct the argument so that it is valid. John is a native-born American All native-born Americans are American Citizens John is an American citizen is an argument in the form of S is P All P are Q S is Q which is a valid form.

b. Fidelity John is Australian John is happy Bad reconstruction: John is Australian All Australians are happy John is happy Satisfactory reconstruction John is Australian Australians tend to be happy-go-lucky folk John is happy

1. Serial Arguments 1 2 3

Eg: We are under attack from implacable enemies, so we need to protect ourselves. That’s why I think the Patriot act is required. Number the three major statements: (1)[We are under attack from implacable enemies], so (2)[we need to protect ourselves.] That’s why (3)[I think the Patriot act is required.] Mark argument indicators: (1)[We are under attack from implacable enemies], so (2)[we need to protect ourselves.] That’s why (3)[I think the Patriot act is required.]

1 2. Divergent Arguments 2 3

We are under attack from implacable enemies, so we need to protect ourselves. I also think that we should fight back. (1)[We are under attack from implacable enemies], so (2)[we need to protect ourselves.] (3)[I also think that we should fight back.] (1)[We are under attack from implacable enemies], so (2)[we need to protect ourselves.] (3)[I also think that we should fight back.] Note that We are under attack from implacable enemies. I also think that we should fight back. Is an argument

3 3. Convergent Arguments 12

To say a reason is independent is to say that if the other reasons fail, that reason will still provide support for the conclusion. A life of crime is not to be desired. Criminals are usually quite unhappy people, and they often come to unpleasant ends. (1)[ A life of crime is not to be desired.] (2)[Criminals are usually quite unhappy people] and (3)[they often come to unpleasant ends.]

3 4. Linked Arguments 12 +

In a linked argument the failure of one reason means that the argument fails because the other reasons do not independently support the conclusion. Socrates is a man and all men are mortal, so Socrates is mortal. (1)[Socrates is a man] and (2)[all men are mortal,] so (3)[Socrates is mortal.] Arguments that claim to provide support for a conclusion by collecting together a large number of rather weak reasons in support of a conclusion are best thought of as linked arguments (rather than convergent.)

Hidden Elements We mark hidden premises or conclusions in a diagram by enclosing the number in square brackets, e.g. 3

United Airlines are on strike, so other airlines will carry more passengers. (1)[United Airlines are on strike], so (2)[other airlines will carry more passengers.] 1 2

But if we include the hidden intermediate conclusion that was suggested earlier, that (3)[The airlines as a whole have to carry so many passengers] then we can see the argument as having the following form

Conditionalisation If we have an argument of the form: A a B then we can deduce the conditional statement ‘If A then B’.

This is the conditionalisation of the argument from A to B: A a B If A then B

Reductio ad absurdum (RAA): A a B If A then B (and B is known to be false) Not B Not A

Here’s an example. Suppose we’re given a statement: I know that I do not know anything. There’s an argument against this that goes: Suppose it’s true that I know that I don’t know anything. If that’s the case then it’s also true that I don’t know that I don’t know anything. So I both know and don’t know that I don’t know anything. But that’s absurd because I can’t both know and not know the very same thing. Thus it can’t be true that I know that I don’t know anything.

We can identify the major statements and indicators in this argument like this: Suppose it’s true that 1 (I know that I don’t know anything.) If 1 (that’s the case) then it’s also true that 2 (I don’t know that I don’t know anything.) So 3 (I both know and don’t know that I don’t know anything.) But 4 (that’s absurd) because 5 (I can’t both know and not know the very same thing.) Thus 5 (it can’t be true that I know that I don’t know anything.)

This argument structure looks like this: If 1 then 3 5 (4 =) Not 3 Not 1

Complex Arguments 1 (In rape cases, sentences should be lighter for those who plead guilty than for those who plead not guilty.) 2 (Appearing in court is a very distressing experience for a victim of rape.) 3 (If the defendant pleads guilty, the victim does not have to appear in court.) 4 (If sentences are as heavy for those who plead guilty as for those who plead not guilty, all defendants will plead not guilty), because 5 (there is nothing to lose.)

1 (Our souls are immortal.) We know this from 2 (revelation), but we also know it by 3 (philosophical argument.) 4 (For example, we can prove the immortality of the soul by simply attending to its indivisibility), for 5 (only composite things can be destroyed) and because 6 (it is pure substance) 7 (the soul is incomposite.)

REASONS AGAINST A CONCLUSION 2 ~ 3 = 2 not 3

We need to generate more electricity Nuclear power plants are very controversial We should build more nuclear power plants ~

Reasons against a reason 4 (If we were more careful users, we wouldn’t need more power) ~ 3 (We need to generate more electric power)

Reasons against an inference 1 (We need to generate more electric power) 5 (Coal-fired power~ stations are much easier to build) 3 (We should build more nuclear power plants)