Conditionals IV: Is Modus Ponens Valid?

Size: px
Start display at page:

Download "Conditionals IV: Is Modus Ponens Valid?"

Transcription

1 Conditionals IV: Is Modus Ponens Valid? UC Berkeley, Philosophy 142, Spring 2016 John MacFarlane 1 The intuitive counterexamples McGee [2] offers these intuitive counterexamples to Modus Ponens: 1. (a) If a Republican will win the election, then if Reagan will not win, Anderson will win. (b) A Republican will win the election. (c) So, if Reagan will not win, Anderson will win. 2. (a) If that creature is a fish, then if it has lungs, it is a lungfish. (b) That creature is a fish. (c) So, if it has lungs, it is a lungfish. 3. (a) If Uncle Otto doesn t find gold, then if he strikes it rich, he will strike it rich by finding silver. (b) Uncle Otto won t find gold. (c) So, if Uncle Otto strikes it rich, he will strike it rich by finding silver. 2 Some important distinctions We have seen from Stalnaker the importance of distinguishing between two questions: 1. If the premises are true at a world, does the conclusion have to be true at that world? 2. If the premises are accepted (true throughout the context set), does the conclusion have to be accepted? Showing (2) doesn t establish (1). We have already seen several examples of inferences that are acceptance-preserving but not truth-preserving. For example, B, therefore if A, then B. Has McGee given us counterexamples to the claim that Modus Ponens is acceptancepreserving? It seems not. Surely, if it is believed with certainty (or accepted or presupposed) that a Republican will win, we must conclude that if Reagan does not win, Anderson will. But, even if MP is acceptance-preserving, it might not be truth-preserving. Suppose that we have good but not conclusive grounds for accepting the premises; that is, grounds for assigning a high probability. Might we still have conclusive grounds for rejecting the conclusion? We can map our credences as follows (bigger area = larger probability): April 14,

2 2. Some important distinctions Carter Reagan Anderson 1. If a Republican will win the election, then if Reagan will not win, Anderson will win. 2. A Republican will win the election. 3. So, if Reagan will not win, Anderson will win. Not a fish Lungs Fish 1. If that creature is a fish, then if it has lungs, it is a lungfish. 2. That creature is a fish. 3. So, if it has lungs, it is a lungfish. Otto finds gold Otto gets rich Otto finds silver 1. If Uncle Otto doesn t find gold, then if he strikes it rich, he will strike it rich by finding silver. 2. Uncle Otto won t find gold. 3. So, if Uncle Otto strikes it rich, he will strike it rich by finding silver. If we apply Edgington s test for the acceptability of an indicative conditional, this will give us cases where the premises are acceptable to a high degree, but the conclusion is not. This answers the question: 3. If we assign high credence to the premises, must we assign high credence to the conclusion? But note that a No answer to (3) doesn t imply a No answer to (1). Compare (for a 6-sided die): The die will not land 1. The die will not land 2. The die will not land 3. The die will not land 4. The die will not land 5. So, the die will land 6. Here we can have a high credence to each premise but a low credence in their conjunction, and hence a low credence in their conclusion. We might ask instead: April 14,

3 3. Direct assessments 4. If we assign high credence to the conjunction of the premises, must we assign high credence to the conclusion? In McGee s cases, do we assign a high credence to the conjunction of the premises? Well, here there are only two premises. Assume that A and A B are probabilistically independent. Then the probability of their conjunction is the product of their probabilities. If we have 0.9 credence in both, then, our credence in their conjunction should be 0.81, which is still fairly high. Note also that the (a) premise in each of McGee s examples seems to be something we might believe with credence 1. 3 Direct assessments Instead of asking about whether it would be okay to infer the conclusions from the premises in McGee s examples, we might try assessing the truth values of the premises and conclusions in different scenarios. It is important to keep in mind here that, on most semantics for the indicative conditional, it will be highly contextually sensitive. For example, on Stalnaker s view, the truth of if A then B can depend on (a) what respects of similarity are contextually relevant and (b) on what has been presupposed (what the context set is). For example, as we have seen, if B is presupposed and A is compatible with what is presupposed, then A B is guaranteed to be true. (The closest A-world will have to be in the context set, and so it will be a B world.) But if B is not presupposed, A B can be false, even if B is true. Now let s suppose that, shortly before the 1980 election, Sarah uttered (1a) and (1b). Suppose that the context set governing her conversation at this time includes worlds where Reagan, worlds where Carter, and worlds where Anderson. As far as she is presupposing, any of the candidates could win. Did she speak truly in uttering (1a)? Plausibly, yes. She knew that Anderson and Reagan were the only Republican candidates. Did she speak truly in uttering (1b)? We know that she did, since Reagan, a Republican, did win the election. Did she speak truly in uttering (1c)? That is harder to answer, since the truth conditions of indicative conditionals are disputed. But let s think about it from the standpoint of Stalnaker s view. What was the closest world to the actual world where Reagan did not win? Presumably it was a world where Carter won, not a world where Anderson did. So (1c) was false, in Sarah s context. Granted, if it had been accepted in Sarah s context that a Republican would win, then (1c) would have been true in her context, because there would be no worlds in the context set where Carter. But let s imagine a case where this is not accepted. (Imagine either that Sarah is not making an assertion in uttering (1b), or that she is making an assertion, but her conversational partners don t accept it.) April 14,

4 4. Modus ponens vs exportation But hold on! We know that on Stalnaker s semantics, modus ponens is valid. If A and A B are both true at a world, B has to be true at that world. And now we re saying that Stalnaker s semantics agrees with McGee that (1c) is false, in the imagined context. So what s going on? Stalnaker will have to deny that either (1b) or (1a) expresses a truth. (1b) is undeniably true, so he will have to reject (1a). If we think about Stalnaker s semantics, it s easy to see that it doesn t vindicate our intuition that Sarah s utterance of (1a) is true. Consider the actual world. It s a world where a Republican will win the election. So (1a) is true at that world if (1c) is true at that world. We have just seen that (1c) is not true at that world, since the closest world where Reagan does not win is a world where Carter. So (1a) is not true either. McGee would say: This doesn t show that we don t have a counterexample to modus ponens. It just shows that Stalnaker s semantics is not right. For clearly (1a) is true in the imagined context. 4 Modus ponens vs exportation McGee argues that if we want a counditional that is stronger than the material conditional and weaker than strict implication, we need to choose between modus ponens and Exportation (A B) C A (B C ) He gives the argument with a great deal of rigor [2, pp ]. The basic idea, though, is very simple (it is similar to an idea from Allan Gibbard s [1]): 1. Suppose A B. 2. (A B) A logically implies B. (fact) 3. So, ((A B) A) B. (StrImp: If φ logically implies ψ, then φ ψ is true) 4. So, (A B) (A B). (Exportation) 5. So, A B. (Modus ponens for from 1 and 4) So, if we have exportation and StrImp, the material conditional implies the indicative! We can fix this by: (a) giving up the assumption that is weaker than strict implication and stronger than. (b) giving up exportation. (c) giving up modus ponens. McGee argues that we should choose (c). Exportation is plausible across the board, he thinks arguing inductively from some examples! Can you think of counterexamples? McGee notes that Stalnaker s semantics does not seem to endores exportation. What would Stalnaker s semantics say about the following two conditionals? April 14,

5 REFERENCES REFERENCES (1) If Reagan hadn t won the election and a Republican had won, it would have been Anderson. (2) If Reagan hadn t won the election, then if a Republican had won, it would have been Anderson. References [1] Allan Gibbard. Two Recent Theories of Conditionals. In: IFS: Conditionals, Belief, Decision, Chance, and Time. Ed. by William L. Harper, Robert Stalnaker, and Glenn Pearce. 1981, pp [2] Vann McGee. A Counterexample to Modus Ponens. In: Journal of Philosophy 82 (1985), pp April 14,

Conditionals II: no truth conditions?

Conditionals II: no truth conditions? Conditionals II: no truth conditions? UC Berkeley, Philosophy 142, Spring 2016 John MacFarlane 1 Arguments for the material conditional analysis As Edgington [1] notes, there are some powerful reasons

More information

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 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

More information

Closure and Epistemic Modals

Closure and Epistemic Modals Closure and Epistemic Modals Justin Bledin and Tamar Lando July 16, 2015 Abstract: According to a popular closure principle for epistemic justification, if one is justified in believing that each premise

More information

This is an electronic version of a paper Journal of Philosophical Logic 43: , 2014.

This is an electronic version of a paper Journal of Philosophical Logic 43: , 2014. This is an electronic version of a paper Journal of Philosophical Logic 43: 979-997, 2014. The following passage occurs on p.994 of the published version: The invalidity of Antecedent Strengthening cannot

More information

In Defense of Truth functional Theory of Indicative Conditionals. Ching Hui Su Postdoctoral Fellow Institution of European and American Studies,

In Defense of Truth functional Theory of Indicative Conditionals. Ching Hui Su Postdoctoral Fellow Institution of European and American Studies, In Defense of Truth functional Theory of Indicative Conditionals Ching Hui Su Postdoctoral Fellow Institution of European and American Studies, Academia Sinica, Taiwan SELLC 2010 Outline Truth functional

More information

Author's personal copy

Author's personal copy Philos Stud (2016) 173:609 628 DOI 10.1007/s11098-015-0510-5 Whether-conditionals Theodore Korzukhin 1 Published online: 28 July 2015 Springer Science+Business Media Dordrecht 2015 Abstract like: In this

More information

Is anything knowable on the basis of understanding alone?

Is anything knowable on the basis of understanding alone? Is anything knowable on the basis of understanding alone? PHIL 83104 November 7, 2011 1. Some linking principles... 1 2. Problems with these linking principles... 2 2.1. False analytic sentences? 2.2.

More information

Presuppositions (Ch. 6, pp )

Presuppositions (Ch. 6, pp ) (1) John left work early again Presuppositions (Ch. 6, pp. 349-365) We take for granted that John has left work early before. Linguistic presupposition occurs when the utterance of a sentence tells the

More information

Ifs and Oughts. 1 Introduction. June 16, 2009

Ifs and Oughts. 1 Introduction. June 16, 2009 Ifs and Oughts NIKO KOLODNY AND JOHN MACFARLANE June 16, 2009 ABSTRACT We consider a paradox involving indicative conditionals ( ifs ) and deontic modals ( oughts ). After considering and rejecting several

More information

CONDITIONAL PROPOSITIONS AND CONDITIONAL ASSERTIONS

CONDITIONAL PROPOSITIONS AND CONDITIONAL ASSERTIONS CONDITIONAL PROPOSITIONS AND CONDITIONAL ASSERTIONS Robert Stalnaker One standard way of approaching the problem of analyzing conditional sentences begins with the assumption that a sentence of this kind

More information

The Problem of Induction and Popper s Deductivism

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.

More information

To tell the truth about conditionals

To tell the truth about conditionals To tell the truth about conditionals Vann McGee If two people are arguing If p, will q? and both are in doubt as to p, Ramsey tells us, 1 they are adding p hypothetically to their stock of knowledge, and

More information

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

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

More information

TWO VERSIONS OF HUME S LAW

TWO VERSIONS OF HUME S LAW DISCUSSION NOTE BY CAMPBELL BROWN JOURNAL OF ETHICS & SOCIAL PHILOSOPHY DISCUSSION NOTE MAY 2015 URL: WWW.JESP.ORG COPYRIGHT CAMPBELL BROWN 2015 Two Versions of Hume s Law MORAL CONCLUSIONS CANNOT VALIDLY

More information

Vagueness and supervaluations

Vagueness and supervaluations Vagueness and supervaluations UC Berkeley, Philosophy 142, Spring 2016 John MacFarlane 1 Supervaluations We saw two problems with the three-valued approach: 1. sharp boundaries 2. counterintuitive consequences

More information

How Gödelian Ontological Arguments Fail

How Gödelian Ontological Arguments Fail How Gödelian Ontological Arguments Fail Matthew W. Parker Abstract. Ontological arguments like those of Gödel (1995) and Pruss (2009; 2012) rely on premises that initially seem plausible, but on closer

More information

Philosophical Perspectives, 14, Action and Freedom, 2000 TRANSFER PRINCIPLES AND MORAL RESPONSIBILITY. Eleonore Stump Saint Louis University

Philosophical Perspectives, 14, Action and Freedom, 2000 TRANSFER PRINCIPLES AND MORAL RESPONSIBILITY. Eleonore Stump Saint Louis University Philosophical Perspectives, 14, Action and Freedom, 2000 TRANSFER PRINCIPLES AND MORAL RESPONSIBILITY Eleonore Stump Saint Louis University John Martin Fischer University of California, Riverside It is

More information

Inference and Evidence 1

Inference and Evidence 1 Inference and Evidence 1 1. The Two Bases of Rationality We have a variety of attitudes to the truth of propositions: believing that p is true, hoping that p be true, desiring that p become true, assuming,

More information

MATH1061/MATH7861 Discrete Mathematics Semester 2, Lecture 5 Valid and Invalid Arguments. Learning Goals

MATH1061/MATH7861 Discrete Mathematics Semester 2, Lecture 5 Valid and Invalid Arguments. Learning Goals MAH1061/MAH7861 Discrete Mathematics Semester 2, 2016 Learning Goals 1. Understand the meaning of necessary and sufficient conditions (carried over from Wednesday). 2. Understand the difference between

More information

Comments on Truth at A World for Modal Propositions

Comments on Truth at A World for Modal Propositions Comments on Truth at A World for Modal Propositions Christopher Menzel Texas A&M University March 16, 2008 Since Arthur Prior first made us aware of the issue, a lot of philosophical thought has gone into

More information

Finite Reasons without Foundations

Finite Reasons without Foundations Finite Reasons without Foundations Ted Poston January 20, 2014 Abstract In this paper I develop a theory of reasons that has strong similarities to Peter Klein s infinitism. The view I develop, Framework

More information

Phil 413: Problem set #1

Phil 413: Problem set #1 Phil 413: Problem set #1 For problems (1) (4b), if the sentence is as it stands false or senseless, change it to a true sentence by supplying quotes and/or corner quotes, or explain why no such alteration

More information

A Liar Paradox. Richard G. Heck, Jr. Brown University

A Liar Paradox. Richard G. Heck, Jr. Brown University A Liar Paradox Richard G. Heck, Jr. Brown University It is widely supposed nowadays that, whatever the right theory of truth may be, it needs to satisfy a principle sometimes known as transparency : Any

More information

UC Berkeley, Philosophy 142, Spring 2016

UC Berkeley, Philosophy 142, Spring 2016 Logical Consequence UC Berkeley, Philosophy 142, Spring 2016 John MacFarlane 1 Intuitive characterizations of consequence Modal: It is necessary (or apriori) that, if the premises are true, the conclusion

More information

SAVING RELATIVISM FROM ITS SAVIOUR

SAVING RELATIVISM FROM ITS SAVIOUR CRÍTICA, Revista Hispanoamericana de Filosofía Vol. XXXI, No. 91 (abril 1999): 91 103 SAVING RELATIVISM FROM ITS SAVIOUR MAX KÖLBEL Doctoral Programme in Cognitive Science Universität Hamburg In his paper

More information

Modus Ponens Defended

Modus Ponens Defended Modus Ponens Defended Justin Bledin June 26, 2014 Abstract: Is modus ponens for the indicative conditional valid? McGee [1985] famously presents several alleged counterexamples to this rule of inference.

More information

There are two common forms of deductively valid conditional argument: modus ponens and modus tollens.

There are two common forms of deductively valid conditional argument: modus ponens and modus tollens. INTRODUCTION TO LOGICAL THINKING Lecture 6: Two types of argument and their role in science: Deduction and induction 1. Deductive arguments Arguments that claim to provide logically conclusive grounds

More information

Modal disagreements. Justin Khoo. Forthcoming in Inquiry

Modal disagreements. Justin Khoo. Forthcoming in Inquiry Modal disagreements Justin Khoo jkhoo@mit.edu Forthcoming in Inquiry Abstract It s often assumed that when one party felicitously rejects an assertion made by another party, the first party thinks that

More information

Counterfactuals and Causation: Transitivity

Counterfactuals and Causation: Transitivity Counterfactuals and Causation: Transitivity By Miloš Radovanovi Submitted to Central European University Department of Philosophy In partial fulfillment of the requirements for the degree of Master of

More information

Ten miners are trapped either in shaft A or in shaft B, but we

Ten miners are trapped either in shaft A or in shaft B, but we c. c THE JOURNAL OF PHILOSOPHY volume cvii, no. 3, march 2010 c. c IFS AND OUGHTS * Ten miners are trapped either in shaft A or in shaft B, but we do not know which. Flood waters threaten to flood the

More information

Believing Epistemic Contradictions

Believing Epistemic Contradictions Believing Epistemic Contradictions Bob Beddor & Simon Goldstein Bridges 2 2015 Outline 1 The Puzzle 2 Defending Our Principles 3 Troubles for the Classical Semantics 4 Troubles for Non-Classical Semantics

More information

(Some More) Vagueness

(Some More) Vagueness (Some More) Vagueness Otávio Bueno Department of Philosophy University of Miami Coral Gables, FL 33124 E-mail: otaviobueno@mac.com Three features of vague predicates: (a) borderline cases It is common

More information

Between the Actual and the Trivial World

Between the Actual and the Trivial World Organon F 23 (2) 2016: xxx-xxx Between the Actual and the Trivial World MACIEJ SENDŁAK Institute of Philosophy. University of Szczecin Ul. Krakowska 71-79. 71-017 Szczecin. Poland maciej.sendlak@gmail.com

More information

Constraining Credences MASSACHUS TS INS E. Sarah Moss. A.B., Harvard University (2002) B.Phil., Oxford University (2004)

Constraining Credences MASSACHUS TS INS E. Sarah Moss. A.B., Harvard University (2002) B.Phil., Oxford University (2004) Constraining Credences MASSACHUS TS INS E OF TECHNOLOGY by Sarah Moss A.B., Harvard University (2002) B.Phil., Oxford University (2004) Submitted to the Department of Linguistics and Philosophy in partial

More information

A Defence of the Ramsey Test

A Defence of the Ramsey Test Defence of the Ramsey Test Richard Bradley bstract ccording to the Ramsey Test hypothesis the conditional claim that if then B is credible just in case it is credible that B, on the supposition that. If

More information

A Puzzle about Knowing Conditionals i. (final draft) Daniel Rothschild University College London. and. Levi Spectre The Open University of Israel

A Puzzle about Knowing Conditionals i. (final draft) Daniel Rothschild University College London. and. Levi Spectre The Open University of Israel A Puzzle about Knowing Conditionals i (final draft) Daniel Rothschild University College London and Levi Spectre The Open University of Israel Abstract: We present a puzzle about knowledge, probability

More information

how to be an expressivist about truth

how to be an expressivist about truth Mark Schroeder University of Southern California March 15, 2009 how to be an expressivist about truth In this paper I explore why one might hope to, and how to begin to, develop an expressivist account

More information

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

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

More information

Justified Inference. Ralph Wedgwood

Justified Inference. Ralph Wedgwood Justified Inference Ralph Wedgwood In this essay, I shall propose a general conception of the kind of inference that counts as justified or rational. This conception involves a version of the idea that

More information

Saying too Little and Saying too Much. Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul

Saying too Little and Saying too Much. Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul Saying too Little and Saying too Much. Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul Umeå University BIBLID [0873-626X (2013) 35; pp. 81-91] 1 Introduction You are going to Paul

More information

Practical Conditionals

Practical Conditionals Practical Conditionals Jamie Dreier This is a very drafty draft, so please don t cite it. Introduction Sometimes we are under conditional requirements to do things. We can express them like this: If p,

More information

Ambiguous Conditionals

Ambiguous Conditionals Ambiguous Conditionals Karolina Krzyżanowska Faculty of Philosophy, University of Groningen k.h.krzyzanowska@rug.nl Abstract According to the Principle of Conditional Non-Contradiction (CNC), unless p

More information

Factual detachment and speaker endorsement

Factual detachment and speaker endorsement Factual detachment and speaker endorsement Cleo Condoravdi Stanford University Joint work with Sven Lauer, Zukunftskolleg, University of Konstanz Logic Colloquium University of Connecticut May 1, 2015

More information

Contextualism and the Epistemological Enterprise

Contextualism and the Epistemological Enterprise Contextualism and the Epistemological Enterprise Michael Blome-Tillmann University College, Oxford Abstract. Epistemic contextualism (EC) is primarily a semantic view, viz. the view that knowledge -ascriptions

More information

THE CASE OF THE MINERS

THE CASE OF THE MINERS DISCUSSION NOTE BY VUKO ANDRIĆ JOURNAL OF ETHICS & SOCIAL PHILOSOPHY DISCUSSION NOTE JANUARY 2013 URL: WWW.JESP.ORG COPYRIGHT VUKO ANDRIĆ 2013 The Case of the Miners T HE MINERS CASE HAS BEEN PUT FORWARD

More information

Basic Concepts and Skills!

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

More information

10. Presuppositions Introduction The Phenomenon Tests for presuppositions

10. Presuppositions Introduction The Phenomenon Tests for presuppositions 10. Presuppositions 10.1 Introduction 10.1.1 The Phenomenon We have encountered the notion of presupposition when we talked about the semantics of the definite article. According to the famous treatment

More information

Conditionals, Predicates and Probability

Conditionals, Predicates and Probability Conditionals, Predicates and Probability Abstract Ernest Adams has claimed that a probabilistic account of validity gives the best account of our intuitive judgements about the validity of arguments. In

More information

Epistemic modals: relativism vs. cloudy contextualism

Epistemic modals: relativism vs. cloudy contextualism Epistemic modals: relativism vs. cloudy contextualism John MacFarlane University of California, Berkeley April 20, 2010 The plan Standard contextualism and The Problem Two solutions: relativism and cloudy

More information

Semantic Entailment and Natural Deduction

Semantic Entailment and Natural Deduction Semantic Entailment and Natural Deduction Alice Gao Lecture 6, September 26, 2017 Entailment 1/55 Learning goals Semantic entailment Define semantic entailment. Explain subtleties of semantic entailment.

More information

The paradoxical associated conditional of enthymemes

The paradoxical associated conditional of enthymemes University of Windsor Scholarship at UWindsor OSSA Conference Archive OSSA 3 May 15th, 9:00 AM - May 17th, 5:00 PM The paradoxical associated conditional of enthymemes Gilbert Plumer Law School Admission

More information

NOTES ON WILLIAMSON: CHAPTER 11 ASSERTION Constitutive Rules

NOTES ON WILLIAMSON: CHAPTER 11 ASSERTION Constitutive Rules NOTES ON WILLIAMSON: CHAPTER 11 ASSERTION 11.1 Constitutive Rules Chapter 11 is not a general scrutiny of all of the norms governing assertion. Assertions may be subject to many different norms. Some norms

More information

John Hawthorne s Knowledge and Lotteries

John Hawthorne s Knowledge and Lotteries John Hawthorne s Knowledge and Lotteries Chapter 1: Introducing the Puzzle 1.1: A Puzzle 1. S knows that S won t have enough money to go on a safari this year. 2. If S knows that S won t have enough money

More information

Critical Thinking. The Four Big Steps. First example. I. Recognizing Arguments. The Nature of Basics

Critical Thinking. The Four Big Steps. First example. I. Recognizing Arguments. The Nature of Basics Critical Thinking The Very Basics (at least as I see them) Dona Warren Department of Philosophy The University of Wisconsin Stevens Point What You ll Learn Here I. How to recognize arguments II. How to

More information

An alternative understanding of interpretations: Incompatibility Semantics

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.

More information

Informational Models in Deontic Logic: A Comment on Ifs and Oughts by Kolodny and MacFarlane

Informational Models in Deontic Logic: A Comment on Ifs and Oughts by Kolodny and MacFarlane Informational Models in Deontic Logic: A Comment on Ifs and Oughts by Kolodny and MacFarlane Karl Pettersson Abstract Recently, in their paper Ifs and Oughts, Niko Kolodny and John MacFarlane have proposed

More information

2. Refutations can be stronger or weaker.

2. Refutations can be stronger or weaker. Lecture 8: Refutation Philosophy 130 October 25 & 27, 2016 O Rourke I. Administrative A. Schedule see syllabus as well! B. Questions? II. Refutation A. Arguments are typically used to establish conclusions.

More information

Philosophical Arguments

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

More information

The myth of the categorical counterfactual

The myth of the categorical counterfactual Philos Stud (2009) 144:281 296 DOI 10.1007/s11098-008-9210-8 The myth of the categorical counterfactual David Barnett Published online: 12 February 2008 Ó Springer Science+Business Media B.V. 2008 Abstract

More information

Module 5. Knowledge Representation and Logic (Propositional Logic) Version 2 CSE IIT, Kharagpur

Module 5. Knowledge Representation and Logic (Propositional Logic) Version 2 CSE IIT, Kharagpur Module 5 Knowledge Representation and Logic (Propositional Logic) Lesson 12 Propositional Logic inference rules 5.5 Rules of Inference Here are some examples of sound rules of inference. Each can be shown

More information

Intuitive evidence and formal evidence in proof-formation

Intuitive evidence and formal evidence in proof-formation Intuitive evidence and formal evidence in proof-formation Okada Mitsuhiro Section I. Introduction. I would like to discuss proof formation 1 as a general methodology of sciences and philosophy, with a

More information

Moore on External Relations

Moore on External Relations Moore on External Relations G. J. Mattey Fall, 2005 / Philosophy 156 The Dogma of Internal Relations Moore claims that there is a dogma held by philosophers such as Bradley and Joachim, that all relations

More information

Artificial Intelligence: Valid Arguments and Proof Systems. Prof. Deepak Khemani. Department of Computer Science and Engineering

Artificial Intelligence: Valid Arguments and Proof Systems. Prof. Deepak Khemani. Department of Computer Science and Engineering Artificial Intelligence: Valid Arguments and Proof Systems Prof. Deepak Khemani Department of Computer Science and Engineering Indian Institute of Technology, Madras Module 02 Lecture - 03 So in the last

More information

Embedded Attitudes *

Embedded Attitudes * Embedded Attitudes * Kyle Blumberg and Ben Holguín September 2018 Abstract This paper presents a puzzle involving embedded attitude reports. We resolve the puzzle by arguing that attitude verbs take restricted

More information

Intuition as Philosophical Evidence

Intuition as Philosophical Evidence Essays in Philosophy Volume 13 Issue 1 Philosophical Methodology Article 17 January 2012 Intuition as Philosophical Evidence Federico Mathías Pailos University of Buenos Aires Follow this and additional

More information

GROUNDING AND LOGICAL BASING PERMISSIONS

GROUNDING AND LOGICAL BASING PERMISSIONS Diametros 50 (2016): 81 96 doi: 10.13153/diam.50.2016.979 GROUNDING AND LOGICAL BASING PERMISSIONS Diego Tajer Abstract. The relation between logic and rationality has recently re-emerged as an important

More information

Norm-Expressivism and the Frege-Geach Problem

Norm-Expressivism and the Frege-Geach Problem Norm-Expressivism and the Frege-Geach Problem I. INTRODUCTION Megan Blomfield M oral non-cognitivism 1 is the metaethical view that denies that moral statements are truth-apt. According to this position,

More information

Instrumental Normativity: In Defense of the Transmission Principle Benjamin Kiesewetter

Instrumental Normativity: In Defense of the Transmission Principle Benjamin Kiesewetter Instrumental Normativity: In Defense of the Transmission Principle Benjamin Kiesewetter This is the penultimate draft of an article forthcoming in: Ethics (July 2015) Abstract: If you ought to perform

More information

Intro Viewed from a certain angle, philosophy is about what, if anything, we ought to believe.

Intro Viewed from a certain angle, philosophy is about what, if anything, we ought to believe. Overview Philosophy & logic 1.2 What is philosophy? 1.3 nature of philosophy Why philosophy Rules of engagement Punctuality and regularity is of the essence You should be active in class It is good to

More information

Study Guides. Chapter 1 - Basic Training

Study Guides. Chapter 1 - Basic Training Study Guides Chapter 1 - Basic Training Argument: A group of propositions is an argument when one or more of the propositions in the group is/are used to give evidence (or if you like, reasons, or grounds)

More information

Saying too Little and Saying too Much Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul

Saying too Little and Saying too Much Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul Saying too Little and Saying too Much Critical notice of Lying, Misleading, and What is Said, by Jennifer Saul Andreas Stokke andreas.stokke@gmail.com - published in Disputatio, V(35), 2013, 81-91 - 1

More information

Inductive Knowledge. Andrew Bacon. July 26, 2018

Inductive Knowledge. Andrew Bacon. July 26, 2018 Inductive Knowledge Andrew Bacon July 26, 2018 Abstract This paper formulates some paradoxes of inductive knowledge. Two responses in particular are explored: According to the first sort of theory, one

More information

What is a counterexample?

What is a counterexample? Lorentz Center 4 March 2013 What is a counterexample? Jan-Willem Romeijn, University of Groningen Joint work with Eric Pacuit, University of Maryland Paul Pedersen, Max Plank Institute Berlin Co-authors

More information

Might Counterfactuals

Might Counterfactuals Might Counterfactuals Antony Eagle 17 September 2007 Abstract A might counterfactual is a sentence of the form If it had been the case that A, it might have been the case that C. Recently, John Hawthorne

More information

Is Logic a Normative Discipline?

Is Logic a Normative Discipline? Is Logic a Normative Discipline? John MacFarlane June 14, 2017 Conference on the Normativity of Logic University of Bergen Please do not cite or circulate without permission I Is logic a normative discipline?

More information

Imprint A PREFACE PARADOX FOR INTENTION. Simon Goldstein. volume 16, no. 14. july, Rutgers University. Philosophers

Imprint A PREFACE PARADOX FOR INTENTION. Simon Goldstein. volume 16, no. 14. july, Rutgers University. Philosophers Philosophers Imprint A PREFACE volume 16, no. 14 PARADOX FOR INTENTION Simon Goldstein Rutgers University 2016, Simon Goldstein This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives

More information

Williams on Supervaluationism and Logical Revisionism

Williams on Supervaluationism and Logical Revisionism Williams on Supervaluationism and Logical Revisionism Nicholas K. Jones Non-citable draft: 26 02 2010. Final version appeared in: The Journal of Philosophy (2011) 108: 11: 633-641 Central to discussion

More information

Noncognitivism in Ethics, by Mark Schroeder. London: Routledge, 251 pp.

Noncognitivism in Ethics, by Mark Schroeder. London: Routledge, 251 pp. Noncognitivism in Ethics, by Mark Schroeder. London: Routledge, 251 pp. Noncognitivism in Ethics is Mark Schroeder s third book in four years. That is very impressive. What is even more impressive is that

More information

Bennett s Ch 7: Indicative Conditionals Lack Truth Values Jennifer Zale, 10/12/04

Bennett s Ch 7: Indicative Conditionals Lack Truth Values Jennifer Zale, 10/12/04 Bennett s Ch 7: Indicative Conditionals Lack Truth Values Jennifer Zale, 10/12/04 38. No Truth Value (NTV) I. Main idea of NTV: Indicative conditionals have no truth conditions and no truth value. They

More information

Abominable KK Failures

Abominable KK Failures Abominable KK Failures Kevin Dorst Massachussetts Institute of Technology kmdorst@mit.edu Forthcoming in Mind Abstract KK is the thesis that if you can know p, you can know that you can know p. Though

More information

Draft of a paper to appear in C. Cellucci, E. Grosholz and I. Ippoliti (eds.), Logic and Knowledge, Cambridge Scholars Publishing.

Draft of a paper to appear in C. Cellucci, E. Grosholz and I. Ippoliti (eds.), Logic and Knowledge, Cambridge Scholars Publishing. Draft of a paper to appear in C. Cellucci, E. Grosholz and I. Ippoliti (eds.), Logic and Knowledge, Cambridge Scholars Publishing. CLASSIFYING AND JUSTIFYING INFERENCE RULES CARLO CELLUCCI SUMMARY: It

More information

Psillos s Defense of Scientific Realism

Psillos s Defense of Scientific Realism Luke Rinne 4/27/04 Psillos and Laudan Psillos s Defense of Scientific Realism In this paper, Psillos defends the IBE based no miracle argument (NMA) for scientific realism against two main objections,

More information

1.6 Validity and Truth

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

More information

Varieties of Apriority

Varieties of Apriority S E V E N T H E X C U R S U S Varieties of Apriority T he notions of a priori knowledge and justification play a central role in this work. There are many ways in which one can understand the a priori,

More information

David E. Alexander and Daniel Johnson, eds. Calvinism and the Problem of Evil.

David E. Alexander and Daniel Johnson, eds. Calvinism and the Problem of Evil. David E. Alexander and Daniel Johnson, eds. Calvinism and the Problem of Evil. Eugene, OR: Wipf and Stock Publishers, 2016. 318 pp. $62.00 (hbk); $37.00 (paper). Walters State Community College As David

More information

On A New Cosmological Argument

On A New Cosmological Argument On A New Cosmological Argument Richard Gale and Alexander Pruss A New Cosmological Argument, Religious Studies 35, 1999, pp.461 76 present a cosmological argument which they claim is an improvement over

More information

From Necessary Truth to Necessary Existence

From Necessary Truth to Necessary Existence Prequel for Section 4.2 of Defending the Correspondence Theory Published by PJP VII, 1 From Necessary Truth to Necessary Existence Abstract I introduce new details in an argument for necessarily existing

More information

University of Groningen. Between "If" and "Then." Krzyzanowska, Karolina

University of Groningen. Between If and Then. Krzyzanowska, Karolina University of Groningen Between "If" and "Then." Krzyzanowska, Karolina IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the

More information

Validity of Inferences *

Validity of Inferences * 1 Validity of Inferences * When the systematic study of inferences began with Aristotle, there was in Greek culture already a flourishing argumentative practice with the purpose of supporting or grounding

More information

Subjunctive credences and semantic humility

Subjunctive credences and semantic humility In Philosophy and Phenomenological Research vol. 87, no. 2 (2013): 251 78. Penultimate version. Subjunctive credences and semantic humility Sarah Moss ssmoss@umich.edu Suppose that I am holding a delicate

More information

HOW TO ANALYZE AN ARGUMENT

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

More information

DEFEASIBLE A PRIORI JUSTIFICATION: A REPLY TO THUROW

DEFEASIBLE A PRIORI JUSTIFICATION: A REPLY TO THUROW The Philosophical Quarterly Vol. 58, No. 231 April 2008 ISSN 0031 8094 doi: 10.1111/j.1467-9213.2007.512.x DEFEASIBLE A PRIORI JUSTIFICATION: A REPLY TO THUROW BY ALBERT CASULLO Joshua Thurow offers a

More information

Part II: How to Evaluate Deductive Arguments

Part II: How to Evaluate Deductive Arguments Part II: How to Evaluate Deductive Arguments Week 4: Propositional Logic and Truth Tables Lecture 4.1: Introduction to deductive logic Deductive arguments = presented as being valid, and successful only

More information

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.

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

More information

Foreknowledge, evil, and compatibility arguments

Foreknowledge, evil, and compatibility arguments Foreknowledge, evil, and compatibility arguments Jeff Speaks January 25, 2011 1 Warfield s argument for compatibilism................................ 1 2 Why the argument fails to show that free will and

More information

Pragmatic Presupposition

Pragmatic Presupposition Pragmatic Presupposition Read: Stalnaker 1974 481: Pragmatic Presupposition 1 Presupposition vs. Assertion The Queen of England is bald. I presuppose that England has a unique queen, and assert that she

More information

Argumentation Module: Philosophy Lesson 7 What do we mean by argument? (Two meanings for the word.) A quarrel or a dispute, expressing a difference

Argumentation Module: Philosophy Lesson 7 What do we mean by argument? (Two meanings for the word.) A quarrel or a dispute, expressing a difference 1 2 3 4 5 6 Argumentation Module: Philosophy Lesson 7 What do we mean by argument? (Two meanings for the word.) A quarrel or a dispute, expressing a difference of opinion. Often heated. A statement of

More information

Constructing the World

Constructing the World Constructing the World Lecture 3: The Case for A Priori Scrutability David Chalmers Plan *1. Sentences vs Propositions 2. Apriority and A Priori Scrutability 3. Argument 1: Suspension of Judgment 4. Argument

More information

Paradox of Deniability

Paradox of Deniability 1 Paradox of Deniability Massimiliano Carrara FISPPA Department, University of Padua, Italy Peking University, Beijing - 6 November 2018 Introduction. The starting elements Suppose two speakers disagree

More information

INTRODUCTION. This week: Moore's response, Nozick's response, Reliablism's response, Externalism v. Internalism.

INTRODUCTION. This week: Moore's response, Nozick's response, Reliablism's response, Externalism v. Internalism. GENERAL PHILOSOPHY WEEK 2: KNOWLEDGE JONNY MCINTOSH INTRODUCTION Sceptical scenario arguments: 1. You cannot know that SCENARIO doesn't obtain. 2. If you cannot know that SCENARIO doesn't obtain, you cannot

More information