# Tutorial A03: Patterns of Valid Arguments By: Jonathan Chan

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 A03.1 Introduction Tutorial A03: Patterns of Valid Arguments By: With valid arguments, it is impossible to have a false conclusion if the premises are all true. Obviously valid arguments play a very important role in reasoning, because if we start with true assumptions, and use only valid arguments to establish new conclusions, then our conclusions must also be true. But which are the rules we should use to decide whether an argument is valid or not? This is where formal logic comes in. By using special symbols we can describe patterns of valid argument, and formulate rules for evaluating the validity of an argument. A03.2 Modus ponens Consider the following arguments: If this object is made of copper, it will conduct electricity. This object is made of copper, so it will conduct electricity. If there is no largest prime number, then is not the largest prime number. There is no largest prime number. Therefore is not the largest prime number. If Lam is a Buddhist then he should not eat pork. Lam is a Buddhist. Therefore Lam should not eat pork. These three arguments are of course valid. Furthermore you probably notice that they are very similar to each other. What is common between them is that they have the same structure or form: Modus ponens - If P then Q. P. Therefore Q. Here, the letters P and Q are called sentence letters. They are used to translate or represent statements. By replacing P and Q with appropriate sentences, we can generate the original three valid arguments. This shows that the three arguments have a common form. It is also in virtue of this form that the arguments are valid, for we can see that any argument of the same form is a valid argument. Because this particular pattern of argument is quite common, it has been given a name. It is known as modus ponens. However, don't confuse modus ponens with the following form of argument, which is not valid! Affirming the consequent - If P then Q. Q. Therefore, P. Note - When we say that this is not a valid pattern of argument, what is meant is that not every argument of this pattern is valid. This is different from saying that every argument of this pattern is not valid. See if you can figure out why this is the case. Giving arguments of this form is a fallacy - making a mistake of reasoning. This particular mistake is known as affirming the consequent.

2 If Jane lives in London then Jane lives in England. Jane lives in England. Therefore Jane lives in London. [Not valid - perhaps Jane lives in Liverpool.] If Bing has gone shopping then Daniel will be unhappy. Daniel is unhappy. So Bing has gone shopping. [Not valid - perhaps Daniel is unhappy because he has run out of vodka to drink.] There are of course many other patterns of valid argument. Now we shall introduce a few more patterns which are often used in reasoning. A03.3 Modus tollens Modus tollens - If P then Q. Not-Q. Therefore, not-p. Here, "not-q" simply means the denial of Q. So if Q means "Today is hot.", then "not-q" can be used to translate "It is not the case that today is hot", or "Today is not hot." If Betty is on the plane, she will be in the A1 seat. But Betty is not in the A1 seat. So she is not on the plane. But do distinguish modus tollens from the following fallacious pattern of argument : Denying the antecedent - If P then Q, not-p. Therefore, not-q. If Elsie is competent, she will get an important job. But Elsie is not competent. So she will not get an important job. [Not valid : Perhaps Elsie is incompetent but her boss likes her because she accepts very low wages.] A03.4 Hypothetical syllogism If P then Q, If Q then R. Therefore, if P then R. If God created the universe then the universe will be perfect. If the universe is perfect then there will be no evil. So if God created the universe there will be no evil. A03.5 Disjunctive syllogism P or Q. Not-P. Therefore, Q ; P or Q, Not-Q. Therefore, P. Either the government brings about more sensible educational reforms, or the only good schools left will be private ones for rich kids. The government is not going to carry out sensible educational reforms. So the only good schools left will be private ones for rich kids. A03.6 Dilemma

3 P or Q. If P then R. If Q then S. Therefore, R or S. When R is the same as S, we have a simpler form : P or Q. If P then R. If Q then R. Therefore, R. Either we increase the tax rate or we don't. If we do, the people will be unhappy. If we don't, the people will also be unhappy. (Because the government will not have enough money to provide for public services.) So the people are going to be unhappy anyway. A03.7 Arguing by Reductio ad Absurdum The Latin name here simply means "reduced to absurdity". Here is the method of argument if you want to prove that a certain statement S is false: First assume that S is true. From the assumption that it is true, prove that it would lead to a contradiction or some other claim that is false or absurd. Conclude that S must be false. Those of you who can spot connections quickly might notice that this is none other than an application of modus tollens. A famous application of this pattern of argument is Euclid's proof that there is no largest prime number. A prime number is any positive integer greater than 1 that is wholly divisible only by 1 and by itself, e.g. 2, 3, 5, 7, 11, 13, 17, etc. Assume that there are only n prime numbers, where n is a finite number : P1 < P2 <... < Pn. Define a number Q that is 1 plus the product of all primes, i.e. Q = 1 + ( P1 x P2 x... x Pn). Q is of course larger than Pn. But Q has to be a prime number also, because (a) when it is divided by any prime number it always leave a remainder of 1, and (b) if it is not divisible by an prime number it cannot be divisible by any non-prime numbers either. So Q is a prime number larger than the largest prime number. But this is a contradiction, so the original assumption that there is a finite number of prime numbers must be wrong. So there must be infinitely many primes. Let us look at two more examples of reductio: Suppose someone were to claim that nothing is true or false. We can show that this must be false as follows : If this person's claim is indeed correct, then there is at least one thing that is true, namely the claim that the person is making. So it can't be that nothing is true or false. So his statement must be false. One theory of how the universe came about is that it developed from a vacuum state in the infinite past. Stephen Hawking thinks that this is false. Here is his argument : in order for the universe to develop from a vacuum state, the vacuum state must have been unstable. (If the vacuum state were a stable one, nothing would come out of it.) But if it was unstable, it would not be a vacuum state, and it would not have lasted an infinite time before becoming unstable. A03.8 Other Patterns

4 There are of course many other patterns of deductively valid arguments. One way to construct more patterns is to combine the ones that we have looked at earlier. For example, we can combine two cases of hypothetical syllogism to obtain the following argument: If P then Q. If Q then R. If R then S. Therefore if P then S. There are also a few other simple but also valid patterns which we have not mentioned: P and Q. Therefore Q. P. Therefore P. Some of you might be surprised to find out that "P. Therefore P." is valid. But think about it carefully - if the conclusion is also a premise, then the conclusion obviously follows from the premise! Of course, this tells us that not all valid arguments are good arguments. How these two concepts are connected is a topic we shall discuss later on. We shall look at a few more complicated patterns of valid arguments in another tutorial. It is understandable that you might not remember all the names of these patterns. But what is important is that you can recognize these argument patterns when you come across them in everyday life, and would not confuse them with patterns of invalid arguments that look similar. A03.9 Exercises Question 1 Consider the following arguments. Identify the forms of all valid arguments. Q1.1. If Jesus loves me, then I love Jesus. I do not love Jesus. Therefore, Jesus does not love me. Q1.2. Either Jimmy is walking the dog or Cathy is feeding the cat (or both). Cathy is feeding the cat. Therefore Jimmy is not walking the dog Q1.3. Either Jimmy is walking the dog or Cathy is feeding the cat. Cathy is not feeding the cat. Therefore Jimmy is walking the dog. Q1.4. If X is a man, then X is a human being. If X is a human being, then X is an animal. Therefore, if X is a man, then X is an animal. Q1.5. If I do not have Yellow Tail sashimi, then I shall have scallop sushi instead. Now, I have Yellow Tail sashimi. So I do not have scallop sushi. Q1.6. If some sheep are black, then some ducks are pink. It is not true that some ducks are pink. Therefore, it is not true that some sheep are black.

5 Q1.7. Either she is right or she is wrong. If she is right, then he is wrong. If she is wrong, then he is also wrong. Therefore, he is wrong either way. Q1.8. Paul is a bachelor. Paul is single. So at least one bachelor is single. Q1.9. Either she is in China or she is in Europe. If she is in China, then she is in Beijing. If she is in Europe, then she is sleeping. Hence, either she is in Beijing or she is sleeping. Question 2 Identify the conclusions that can be drawn from these assumptions. Which basic patterns of valid arguments should be used to derive the conclusion? If God is perfect, then God knows what people intend to do in the future. If God knows what people intend to do in the future, then God can stop people from bringing about evil. If he is dead, then there will be no pulse. If there is no pulse, then the red light will turn on. There is no red light. Either Krypto is hot or Pluto is hot. If Krypto is hot, then there is no ice on its surface. But there is. Either you speak justly or unjustly. If you speak justly then men will hate you. But if you speak unjustly the gods will hate you. Johannes is either in Hong Kong or in Thailand. He is not at home. If he is in Thailand he is staying at the Peninsula. If he is in Hong Kong he is at home. Question 3 If the following statements are all true, who killed Pam and where was Jones in 1997? Which piece of information is not needed? Jones was either in HK or in London in If Jones did not kill Pam, then Peter did. If Pam died of suffocation, then either Jones killed her, or Pam committed suicide. If Jones was in HK in 1997, then Jones did not kill Pam. Pam died of suffocation but she did not kill herself. Question 4 Suppose someone thinks that there is only a finite number of integers. How would he criticize the proof that there are infinitely many primes? Which step would he reject? Question 5 Here is a very nice example taken from the philosopher James Pryor: A computer scientist announces that he's constructed a computer program that can play the perfect game of chess: he claims that this program is guaranteed to win every game it plays, whether it plays black or white, with never a loss or a draw, and against any opponent whatsoever. The computer scientist claims to have a mathematical proof that his program will always win, but the proof runs to 500 pages of dense mathematical symbols, and no one has yet been able to verify it. Still, the program has just played 20 games against Gary Kasparov and it won every game, 10 as white and 10 as black. Should you believe the computer scientist's claim that the program is so designed that it will always win against every opponent? How would you use the reduction method to argue against the computer scientist?

6 What if two computers running the same program were to play against each other?

### Selections from Aristotle s Prior Analytics 41a21 41b5

Lesson Seventeen The Conditional Syllogism Selections from Aristotle s Prior Analytics 41a21 41b5 It is clear then that the ostensive syllogisms are effected by means of the aforesaid figures; these considerations

### PHILOSOPHY 102 INTRODUCTION TO LOGIC PRACTICE EXAM 1. W# Section (10 or 11) 4. T F The statements that compose a disjunction are called conjuncts.

PHILOSOPHY 102 INTRODUCTION TO LOGIC PRACTICE EXAM 1 W# Section (10 or 11) 1. True or False (5 points) Directions: Circle the letter next to the best answer. 1. T F All true statements are valid. 2. T

### Chapter 8 - Sentential Truth Tables and Argument Forms

Logic: A Brief Introduction Ronald L. Hall Stetson University Chapter 8 - Sentential ruth ables and Argument orms 8.1 Introduction he truth-value of a given truth-functional compound proposition depends

### Relevance. Premises are relevant to the conclusion when the truth of the premises provide some evidence that the conclusion is true

Relevance Premises are relevant to the conclusion when the truth of the premises provide some evidence that the conclusion is true Premises are irrelevant when they do not 1 Non Sequitur Latin for it does

### HOW TO ANALYZE AN ARGUMENT

What does it mean to provide an argument for a statement? To provide an argument for a statement is an activity we carry out both in our everyday lives and within the sciences. We provide arguments for

### Philosophical Arguments

Philosophical Arguments An introduction to logic and philosophical reasoning. Nathan D. Smith, PhD. Houston Community College Nathan D. Smith. Some rights reserved You are free to copy this book, to distribute

### Session 10 INDUCTIVE REASONONING IN THE SCIENCES & EVERYDAY LIFE( PART 1)

UGRC 150 CRITICAL THINKING & PRACTICAL REASONING Session 10 INDUCTIVE REASONONING IN THE SCIENCES & EVERYDAY LIFE( PART 1) Lecturer: Dr. Mohammed Majeed, Dept. of Philosophy & Classics, UG Contact Information:

### HANDBOOK (New or substantially modified material appears in boxes.)

1 HANDBOOK (New or substantially modified material appears in boxes.) I. ARGUMENT RECOGNITION Important Concepts An argument is a unit of reasoning that attempts to prove that a certain idea is true by

### Chapter 1. Introduction. 1.1 Deductive and Plausible Reasoning Strong Syllogism

Contents 1 Introduction 3 1.1 Deductive and Plausible Reasoning................... 3 1.1.1 Strong Syllogism......................... 3 1.1.2 Weak Syllogism.......................... 4 1.1.3 Transitivity

### MCQ IN TRADITIONAL LOGIC. 1. Logic is the science of A) Thought. B) Beauty. C) Mind. D) Goodness

MCQ IN TRADITIONAL LOGIC FOR PRIVATE REGISTRATION TO BA PHILOSOPHY PROGRAMME 1. Logic is the science of-----------. A) Thought B) Beauty C) Mind D) Goodness 2. Aesthetics is the science of ------------.

### Unit. Categorical Syllogism. What is a syllogism? Types of Syllogism

Unit 8 Categorical yllogism What is a syllogism? Inference or reasoning is the process of passing from one or more propositions to another with some justification. This inference when expressed in language

What is an argument? PHIL 110 Lecture on Chapter 3 of How to think about weird things An argument is a collection of two or more claims, one of which is the conclusion and the rest of which are the premises.

### Chapter 9- Sentential Proofs

Logic: A Brief Introduction Ronald L. Hall, Stetson University Chapter 9- Sentential roofs 9.1 Introduction So far we have introduced three ways of assessing the validity of truth-functional arguments.

### Logic: A Brief Introduction

Logic: A Brief Introduction Ronald L. Hall, Stetson University PART III - Symbolic Logic Chapter 7 - Sentential Propositions 7.1 Introduction What has been made abundantly clear in the previous discussion

### A short introduction to formal logic

A short introduction to formal logic Dan Hicks v0.3.2, July 20, 2012 Thanks to Tim Pawl and my Fall 2011 Intro to Philosophy students for feedback on earlier versions. My approach to teaching logic has

### 4.1 A problem with semantic demonstrations of validity

4. Proofs 4.1 A problem with semantic demonstrations of validity Given that we can test an argument for validity, it might seem that we have a fully developed system to study arguments. However, there

### In view of the fact that IN CLASS LOGIC EXERCISES

IN CLASS LOGIC EXERCISES Instructions: Determine whether the following are propositions. If some are not propositions, see if they can be rewritten as propositions. (1) I have a very refined sense of smell.

### Handout 1: Arguments -- the basics because, since, given that, for because Given that Since for Because

Handout 1: Arguments -- the basics It is useful to think of an argument as a list of sentences.[1] The last sentence is the conclusion, and the other sentences are the premises. Thus: (1) No professors

### b) The meaning of "child" would need to be taken in the sense of age, as most people would find the idea of a young child going to jail as wrong.

Explanation for Question 1 in Quiz 8 by Norva Lo - Tuesday, 18 September 2012, 9:39 AM The following is the solution for Question 1 in Quiz 8: (a) Which term in the argument is being equivocated. (b) What

### Phil 3304 Introduction to Logic Dr. David Naugle. Identifying Arguments i

Phil 3304 Introduction to Logic Dr. David Naugle Identifying Arguments Dallas Baptist University Introduction Identifying Arguments i Any kid who has played with tinker toys and Lincoln logs knows that

### Practice Test Three Spring True or False True = A, False = B

Practice Test Three Spring 2015 True or False True = A, False = B 1. A sound argument is a valid deductive argument with true premisses. 2. A conclusion is a statement of support. 3. An easy way to determine

### Introduction to Logic

University of Notre Dame Fall, 2015 Arguments Philosophy is difficult. If questions are easy to decide, they usually don t end up in philosophy The easiest way to proceed on difficult questions is to formulate

### PHIL 115: Philosophical Anthropology. I. Propositional Forms (in Stoic Logic) Lecture #4: Stoic Logic

HIL 115: hilosophical Anthropology Lecture #4: Stoic Logic Arguments from the Euthyphro: Meletus Argument (according to Socrates) [3a-b] Argument: Socrates is a maker of gods; so, Socrates corrupts the

### INTERMEDIATE LOGIC Glossary of key terms

1 GLOSSARY INTERMEDIATE LOGIC BY JAMES B. NANCE INTERMEDIATE LOGIC Glossary of key terms This glossary includes terms that are defined in the text in the lesson and on the page noted. It does not include

### Announcements. CS311H: Discrete Mathematics. First Order Logic, Rules of Inference. Satisfiability, Validity in FOL. Example.

Announcements CS311H: Discrete Mathematics First Order Logic, Rules of Inference Instructor: Işıl Dillig Homework 1 is due now! Homework 2 is handed out today Homework 2 is due next Wednesday Instructor:

### Basic Concepts and Skills!

Basic Concepts and Skills! Critical Thinking tests rationales,! i.e., reasons connected to conclusions by justifying or explaining principles! Why do CT?! Answer: Opinions without logical or evidential

### 1. To arrive at the truth we have to reason correctly. 2. Logic is the study of correct reasoning. B. DEDUCTIVE AND INDUCTIVE ARGUMENTS

I. LOGIC AND ARGUMENTATION 1 A. LOGIC 1. To arrive at the truth we have to reason correctly. 2. Logic is the study of correct reasoning. 3. It doesn t attempt to determine how people in fact reason. 4.

### Section 3.5. Symbolic Arguments. Copyright 2013, 2010, 2007, Pearson, Education, Inc.

Section 3.5 Symbolic Arguments What You Will Learn Symbolic arguments Standard forms of arguments 3.5-2 Symbolic Arguments A symbolic argument consists of a set of premises and a conclusion. It is called

### The Philosopher s World Cup

The Philosopher s World Cup Monty Python & the Flying Circus http://www.youtube.com/watch?v=92vv3qgagck&feature=related What is an argument? http://www.youtube.com/watch?v=kqfkti6gn9y What is an argument?

### Unit 4. Reason as a way of knowing. Tuesday, March 4, 14

Unit 4 Reason as a way of knowing I. Reasoning At its core, reasoning is using what is known as building blocks to create new knowledge I use the words logic and reasoning interchangeably. Technically,

### Argument and Persuasion. Stating Opinions and Proposals

Argument and Persuasion Stating Opinions and Proposals The Method It all starts with an opinion - something that people can agree or disagree with. The Method Move to action Speak your mind Convince someone

### What is the Nature of Logic? Judy Pelham Philosophy, York University, Canada July 16, 2013 Pan-Hellenic Logic Symposium Athens, Greece

What is the Nature of Logic? Judy Pelham Philosophy, York University, Canada July 16, 2013 Pan-Hellenic Logic Symposium Athens, Greece Outline of this Talk 1. What is the nature of logic? Some history

### PHILOSOPHER S TOOL KIT 1. ARGUMENTS PROFESSOR JULIE YOO 1.1 DEDUCTIVE VS INDUCTIVE ARGUMENTS

PHILOSOPHER S TOOL KIT PROFESSOR JULIE YOO 1. Arguments 1.1 Deductive vs Induction Arguments 1.2 Common Deductive Argument Forms 1.3 Common Inductive Argument Forms 1.4 Deduction: Validity and Soundness

### Video: How does understanding whether or not an argument is inductive or deductive help me?

Page 1 of 10 10b Learn how to evaluate verbal and visual arguments. Video: How does understanding whether or not an argument is inductive or deductive help me? Download transcript Three common ways to

### Lecture 17:Inference Michael Fourman

Lecture 17:Inference Michael Fourman 2 Is this a valid argument? Assumptions: If the races are fixed or the gambling houses are crooked, then the tourist trade will decline. If the tourist trade declines

### Logic, reasoning and fallacies. Example 0: valid reasoning. Decide how to make a random choice. Valid reasoning. Random choice of X, Y, Z, n

Logic, reasoning and fallacies and some puzzling Before we start Introductory Examples Karst Koymans Informatics Institute University of Amsterdam (version 16.3, 2016/11/21 12:58:26) Wednesday, November

### 9 Methods of Deduction

M09_COPI1396_13_SE_C09.QXD 10/19/07 3:46 AM Page 372 9 Methods of Deduction 9.1 Formal Proof of Validity 9.2 The Elementary Valid Argument Forms 9.3 Formal Proofs of Validity Exhibited 9.4 Constructing

### 5.6.1 Formal validity in categorical deductive arguments

Deductive arguments are commonly used in various kinds of academic writing. In order to be able to perform a critique of deductive arguments, we will need to understand their basic structure. As will be

### CRITICAL THINKING. Formal v Informal Fallacies

CRITICAL THINKING FAULTY REASONING (VAUGHN CH. 5) LECTURE PROFESSOR JULIE YOO Formal v Informal Fallacies Irrelevant Premises Genetic Fallacy Composition Division Appeal to the Person (ad hominem/tu quoque)

### Genuine dichotomies expressed using either/or statements are always true:

CRITICAL THINKING HANDOUT 13 DILEMMAS You re either part of the solution or you re part of the problem Attributed to Eldridge Cleaver, 1968 Over time it s going to be important for nations to know they

### Argument Forms. 1.2 Forms and Validity

1.2 Forms and Validity Deductive logic is the study of methods for determining whether or not an argument is valid. This section introduces the concept of an argument form and explains how an understanding

### 1.5. Argument Forms: Proving Invalidity

18. If inflation heats up, then interest rates will rise. If interest rates rise, then bond prices will decline. Therefore, if inflation heats up, then bond prices will decline. 19. Statistics reveal that

### Does God exist? The argument from evil

Does God exist? The argument from evil There are two especially important arguments against belief in God. The first is based on the (alleged) lack of evidence for God s existence, and the rule that one

### Chapter 5: Ways of knowing Reason (p. 111)

Chapter 5: Ways of knowing Reason (p. 111) Neils Bohr (1885 1962) to Einstein: You are not thinking. You are merely being logical. Reason is one of the four ways of knowing: Perception Language Emotion

### The Little Logic Book Hardy, Ratzsch, Konyndyk De Young and Mellema The Calvin College Press, 2013

The Little Logic Book Hardy, Ratzsch, Konyndyk De Young and Mellema The Calvin College Press, 2013 Exercises for The Little Logic Book may be downloaded by the instructor as Word documents and then modified

### Exposition of Symbolic Logic with Kalish-Montague derivations

An Exposition of Symbolic Logic with Kalish-Montague derivations Copyright 2006-13 by Terence Parsons all rights reserved Aug 2013 Preface The system of logic used here is essentially that of Kalish &

### The Problem of Induction and Popper s Deductivism

The Problem of Induction and Popper s Deductivism Issues: I. Problem of Induction II. Popper s rejection of induction III. Salmon s critique of deductivism 2 I. The problem of induction 1. Inductive vs.

### Replies to Hasker and Zimmerman. Trenton Merricks. Molinism: The Contemporary Debate edited by Ken Perszyk. Oxford University Press, I.

Replies to Hasker and Zimmerman Trenton Merricks Molinism: The Contemporary Debate edited by Ken Perszyk. Oxford University Press, 2011. I. Hasker Here is how arguments by reductio work: you show that

### 1.6 Validity and Truth

M01_COPI1396_13_SE_C01.QXD 10/10/07 9:48 PM Page 30 30 CHAPTER 1 Basic Logical Concepts deductive arguments about probabilities themselves, in which the probability of a certain combination of events is

### I. What is an Argument?

I. What is an Argument? In philosophy, an argument is not a dispute or debate, but rather a structured defense of a claim (statement, assertion) about some topic. When making an argument, one does not

### Cosmological arguments for the Existence of God Gerald Jones Dialogue Issue 26 April 2006

Cosmological arguments for the Existence of God Gerald Jones Dialogue Issue 26 April 2006 In its most basic form, a cosmological argument attempts to understand and answer the question 'Why is there a

### MITOCW Lec 2 MIT 6.042J Mathematics for Computer Science, Fall 2010

MITOCW Lec 2 MIT 6.042J Mathematics for Computer Science, Fall 2010 The following content is provided under a Creative Commons license. Your support will help MIT OpenCourseWare continue to offer high

### Does God exist? The argument from evil

Does God exist? The argument from evil One of the oldest, and most important, arguments against the existence of God tries to show that the idea that God is all-powerful and all-good contradicts a very

### Practice Test Three Fall True or False True = A, False = B

Practice Test Three Fall 2015 True or False True = A, False = B 1. The inclusive "or" means "A or B or both A and B." 2. The conclusion contains both the major term and the middle term. 3. "If, then" statements

### Logic: Deductive and Inductive by Carveth Read M.A. CHAPTER IX CHAPTER IX FORMAL CONDITIONS OF MEDIATE INFERENCE

CHAPTER IX CHAPTER IX FORMAL CONDITIONS OF MEDIATE INFERENCE Section 1. A Mediate Inference is a proposition that depends for proof upon two or more other propositions, so connected together by one or

### Lay75879_ch01 11/17/03 2:03 PM Page x

Lay75879_ch01 11/17/03 2:03 PM Page x McGraw-Hill Higher Education Layman: The Power of Logic, 3e CHAPTER 1 / Page x Lay75879_ch01 11/17/03 2:03 PM Page 1 McGraw-Hill Higher Education Layman: The Power

This article was downloaded by: [Wayne State University] On: 29 August 2011, At: 05:20 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer

### Logic and Argument Analysis: An Introduction to Formal Logic and Philosophic Method (REVISED)

Carnegie Mellon University Research Showcase @ CMU Department of Philosophy Dietrich College of Humanities and Social Sciences 1985 Logic and Argument Analysis: An Introduction to Formal Logic and Philosophic

### Suppressed premises in real life. Philosophy and Logic Section 4.3 & Some Exercises

Suppressed premises in real life Philosophy and Logic Section 4.3 & Some Exercises Analyzing inferences: finale Suppressed premises: from mechanical solutions to elegant ones Practicing on some real-life

### Descartes and Foundationalism

Cogito, ergo sum Who was René Descartes? 1596-1650 Life and Times Notable accomplishments modern philosophy mind body problem epistemology physics inertia optics mathematics functions analytic geometry

### Truth and Molinism * Trenton Merricks. Molinism: The Contemporary Debate edited by Ken Perszyk. Oxford University Press, 2011.

Truth and Molinism * Trenton Merricks Molinism: The Contemporary Debate edited by Ken Perszyk. Oxford University Press, 2011. According to Luis de Molina, God knows what each and every possible human would

### Ethical Consistency and the Logic of Ought

Ethical Consistency and the Logic of Ought Mathieu Beirlaen Ghent University In Ethical Consistency, Bernard Williams vindicated the possibility of moral conflicts; he proposed to consistently allow for

### A Judgmental Formulation of Modal Logic

A Judgmental Formulation of Modal Logic Sungwoo Park Pohang University of Science and Technology South Korea Estonian Theory Days Jan 30, 2009 Outline Study of logic Model theory vs Proof theory Classical

### A Critique of Friedman s Critics Lawrence A. Boland

Revised final draft A Critique of Friedman s Critics Milton Friedman s essay The methodology of positive economics [1953] is considered authoritative by almost every textbook writer who wishes to discuss

### A Brief Introduction to Key Terms

1 A Brief Introduction to Key Terms 5 A Brief Introduction to Key Terms 1.1 Arguments Arguments crop up in conversations, political debates, lectures, editorials, comic strips, novels, television programs,

### What we want to know is: why might one adopt this fatalistic attitude in response to reflection on the existence of truths about the future?

Fate and free will From the first person point of view, one of the most obvious, and important, facts about the world is that some things are up to us at least sometimes, we are able to do one thing, and

### Relativism and the Nature of Truth

Relativism and the Nature of Truth by Roger L. Smalling, D.Min Truth exists Any other premise is self-invalidating. Take, for instance, the thought: Truth does not exist. Is that statement a truth? If

### A. Problem set #3 it has been posted and is due Tuesday, 15 November

Lecture 9: Propositional Logic I Philosophy 130 1 & 3 November 2016 O Rourke & Gibson I. Administrative A. Problem set #3 it has been posted and is due Tuesday, 15 November B. I am working on the group

### Faith indeed tells what the senses do not tell, but not the contrary of what they see. It is above them and not contrary to them.

19 Chapter 3 19 CHAPTER 3: Logic Faith indeed tells what the senses do not tell, but not the contrary of what they see. It is above them and not contrary to them. The last proceeding of reason is to recognize

### The Problem of Major Premise in Buddhist Logic

The Problem of Major Premise in Buddhist Logic TANG Mingjun The Institute of Philosophy Shanghai Academy of Social Sciences Shanghai, P.R. China Abstract: This paper is a preliminary inquiry into the main

### Introduction to Philosophy. Spring 2017

Introduction to Philosophy Spring 2017 Elements of The Matrix The Matrix obviously has a lot of interesting parallels, themes, philosophical points, etc. For this class, the most interesting are the religious

### Chapter 3: Basic Propositional Logic. Based on Harry Gensler s book For CS2209A/B By Dr. Charles Ling;

Chapter 3: Basic Propositional Logic Based on Harry Gensler s book For CS2209A/B By Dr. Charles Ling; cling@csd.uwo.ca The Ultimate Goals Accepting premises (as true), is the conclusion (always) true?

### Does the Third Man Argument refute the theory of forms?

Does the Third Man Argument refute the theory of forms? Fine [1993] recognises four versions of the Third Man Argument (TMA). However, she argues persuasively that these are similar arguments with similar

### Thirty - Eight Ways to Win an Argument from Schopenhauer's "The Art of Controversy"...per fas et nefas :-)

Page 1 of 5 Thirty - Eight Ways to Win an Argument from Schopenhauer's "The Art of Controversy"...per fas et nefas :-) (Courtesy of searchlore ~ Back to the trolls lore ~ original german text) 1 Carry

### LOGICAL FALLACIES/ERRORS OF ARGUMENT

LOGICAL FALLACIES/ERRORS OF ARGUMENT Deduction Fallacies Term Definition Example(s) 1 Equivocation Ambiguity 2 types: The word or phrase may be ambiguous, in which case it has more than one distinct meaning

### Lemon Bay High School AP Language and Composition ENC 1102 Mr. Hertz

Lemon Bay High School AP Language and Composition ENC 1102 Mr. Hertz Please take out a few pieces of paper and a pen or pencil. Write your name, the date, your class period, and a title at the top of the

### Alice E. Fischer. CSCI 1166 Discrete Mathematics for Computing February, 2018

Alice E. Fischer CSCI 1166 Discrete Mathematics for Computing February, 2018 Alice E. Fischer... 1/28 1 Examples and Varieties Order of Quantifiers and Negations 2 3 Universal Existential 4 Universal Modus

### A GNOSTIC CHRISTIANITY

Oct. 9, 2014; 4 pm. Seminar at the Department for the Study of Religions, University of Szeged, Petőfi Sándor avenue 30-34, Petőfi building, first floor, room II. A GNOSTIC CHRISTIANITY Some developing

### Three Kinds of Arguments

Chapter 27 Three Kinds of Arguments Arguments in general We ve been focusing on Moleculan-analyzable arguments for several chapters, but now we want to take a step back and look at the big picture, at

### Descartes Method of Doubt

Descartes Method of Doubt Philosophy 100 Lecture 9 PUTTING IT TOGETHER. Descartes Idea 1. The New Science. What science is about is describing the nature and interaction of the ultimate constituents of

### Statistical Syllogistic, Part 1

University of Windsor Scholarship at UWindsor OSSA Conference Archive OSSA 4 May 17th, 9:00 AM - May 19th, 5:00 PM Statistical Syllogistic, Part 1 Lawrence H. Powers Follow this and additional works at:

### Logical (formal) fallacies

Fallacies in academic writing Chad Nilep There are many possible sources of fallacy an idea that is mistakenly thought to be true, even though it may be untrue in academic writing. The phrase logical fallacy

### Cosmological Argument

Theistic Arguments: The Craig Program, 2 Edwin Chong February 27, 2005 Cosmological Argument God makes sense of the origin of the universe. Kalam cosmological argument. [Craig 1979] Kalam: An Arabic term

### I Don't Believe in God I Believe in Science

I Don't Believe in God I Believe in Science This seems to be a common world view that many people hold today. It is important that when we look at statements like this we spend a proper amount of time

### 6: DEDUCTIVE LOGIC. Chapter 17: Deductive validity and invalidity Ben Bayer Drafted April 25, 2010 Revised August 23, 2010

6: DEDUCTIVE LOGIC Chapter 17: Deductive validity and invalidity Ben Bayer Drafted April 25, 2010 Revised August 23, 2010 Deduction vs. induction reviewed In chapter 14, we spent a fair amount of time

### Denying the Antecedent as a Legitimate Argumentative Strategy: A Dialectical Model

Denying the Antecedent as a Legitimate Argumentative Strategy 219 Denying the Antecedent as a Legitimate Argumentative Strategy: A Dialectical Model DAVID M. GODDEN DOUGLAS WALTON University of Windsor

### 10 CERTAINTY G.E. MOORE: SELECTED WRITINGS

10 170 I am at present, as you can all see, in a room and not in the open air; I am standing up, and not either sitting or lying down; I have clothes on, and am not absolutely naked; I am speaking in a

### An alternative understanding of interpretations: Incompatibility Semantics

An alternative understanding of interpretations: Incompatibility Semantics 1. In traditional (truth-theoretic) semantics, interpretations serve to specify when statements are true and when they are false.

### A BRIEF INTRODUCTION TO LOGIC FOR METAPHYSICIANS

A BRIEF INTRODUCTION TO LOGIC FOR METAPHYSICIANS 0. Logic, Probability, and Formal Structure Logic is often divided into two distinct areas, inductive logic and deductive logic. Inductive logic is concerned

### The problems of induction in scientific inquiry: Challenges and solutions. Table of Contents 1.0 Introduction Defining induction...

The problems of induction in scientific inquiry: Challenges and solutions Table of Contents 1.0 Introduction... 2 2.0 Defining induction... 2 3.0 Induction versus deduction... 2 4.0 Hume's descriptive

### Introductory Matters

1 Introductory Matters The readings in this section take up some topics that set the stage for discussion to follow. The first addresses the value of philosophy, the second the nature of truth, and the

### Worksheet Exercise 1.1. Logic Questions

Worksheet Exercise 1.1. Logic Questions Date Study questions. These questions do not have easy answers. (But that doesn't mean that they have no answers.) Just think about these issues. There is no particular

### Symbolic Logic. 8.1 Modern Logic and Its Symbolic Language

M08_COPI1396_13_SE_C08.QXD 10/16/07 9:19 PM Page 315 Symbolic Logic 8 8.1 Modern Logic and Its Symbolic Language 8.2 The Symbols for Conjunction, Negation, and Disjunction 8.3 Conditional Statements and

### Spinoza, Ethics 1 of 85 THE ETHICS. by Benedict de Spinoza (Ethica Ordine Geometrico Demonstrata) Translated from the Latin by R. H. M.

Spinoza, Ethics 1 of 85 THE ETHICS by Benedict de Spinoza (Ethica Ordine Geometrico Demonstrata) Translated from the Latin by R. H. M. Elwes PART I: CONCERNING GOD DEFINITIONS (1) By that which is self-caused

### Moral Argument. Theistic Arguments: The Craig Program, 4. Edwin Chong. God makes sense of the objective moral values in the world.

Theistic Arguments: The Craig Program, 4 Edwin Chong March 13, 2005 Moral Argument God makes sense of the objective moral values in the world. March 2005 2 1 The Argument If God does not exist, objective

### Boghossian & Harman on the analytic theory of the a priori

Boghossian & Harman on the analytic theory of the a priori PHIL 83104 November 2, 2011 Both Boghossian and Harman address themselves to the question of whether our a priori knowledge can be explained in

### Exercise Sets. KS Philosophical Logic: Modality, Conditionals Vagueness. Dirk Kindermann University of Graz July 2014

Exercise Sets KS Philosophical Logic: Modality, Conditionals Vagueness Dirk Kindermann University of Graz July 2014 1 Exercise Set 1 Propositional and Predicate Logic 1. Use Definition 1.1 (Handout I Propositional