Philosophy 1100: Ethics

Similar documents
Revisiting the Socrates Example

Chapter 1. What is Philosophy? Thinking Philosophically About Life

Introduction to Logic

Selections from Aristotle s Prior Analytics 41a21 41b5

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.

Introduction to Logic

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

HOW TO ANALYZE AN ARGUMENT

Lecture 3 Arguments Jim Pryor What is an Argument? Jim Pryor Vocabulary Describing Arguments

Philosophy 1100: Introduction to Ethics. Critical Thinking Lecture 1. Background Material for the Exercise on Validity

Overview of Today s Lecture

CHAPTER THREE Philosophical Argument

A short introduction to formal logic

Logic Appendix: More detailed instruction in deductive logic

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

In view of the fact that IN CLASS LOGIC EXERCISES

A Primer on Logic Part 1: Preliminaries and Vocabulary. Jason Zarri. 1. An Easy $10.00? a 3 c 2. (i) (ii) (iii) (iv)

What is an argument? PHIL 110. Is this an argument? Is this an argument? What about this? And what about this?

Part 2 Module 4: Categorical Syllogisms

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

Pastor-teacher Don Hargrove Faith Bible Church September 8, 2011

Logic Book Part 1! by Skylar Ruloff!

Philosophical Arguments

Venn Diagrams and Categorical Syllogisms. Unit 5

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

Introduction to Philosophy

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

The antecendent always a expresses a sufficient condition for the consequent

Baronett, Logic (4th ed.) Chapter Guide

PHIL2642 CRITICAL THINKING USYD NOTES PART 1: LECTURE NOTES

PHI 1500: Major Issues in Philosophy

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

Study Guides. Chapter 1 - Basic Training

16. Universal derivation

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

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

Logic: A Brief Introduction. Ronald L. Hall, Stetson University

Thinking and Reasoning

Test Item File. Full file at

Tutorial A03: Patterns of Valid Arguments By: Jonathan Chan

PLEASE DO NOT WRITE ON THIS QUIZ

Ethics and Science. Obstacles to search for truth. Ethics: Basic Concepts 1

CRITICAL THINKING (CT) MODEL PART 1 GENERAL CONCEPTS

To better understand VALIDITY, we now turn to the topic of logical form.

Also, in Argument #1 (Lecture 11, Slide 11), the inference from steps 2 and 3 to 4 is stated as:

UBC - OKANAGAN. COURSE OUTLINE Summer 2013 PHILOSOPHY BIOMEDICAL ETHICS

Philosophical Methods Revised: August, 2018

HANDBOOK. IV. Argument Construction Determine the Ultimate Conclusion Construct the Chain of Reasoning Communicate the Argument 13

Deduction. Of all the modes of reasoning, deductive arguments have the strongest relationship between the premises

SYLLOGISTIC LOGIC CATEGORICAL PROPOSITIONS

Recall. Validity: If the premises are true the conclusion must be true. Soundness. Valid; and. Premises are true

1/19/2011. Concept. Analysis

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

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

Part II: How to Evaluate Deductive Arguments

EXERCISES: (from

INTRODUCTION TO PHILOSOPHY MEANING NATURE SCOPE GOALS IMPORTANCE BRANCHES EPOCH

Announcements. CS243: Discrete Structures. First Order Logic, Rules of Inference. Review of Last Lecture. Translating English into First-Order Logic

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

Introducing Our New Faculty

Norva Y S Lo Produced by Norva Y S Lo Edited by Andrew Brennan

L4: Reasoning. Dani Navarro

Deductive Forms: Elementary Logic By R.A. Neidorf READ ONLINE

Logic: The Science that Evaluates Arguments

GENERAL NOTES ON THIS CLASS

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

4.1 A problem with semantic demonstrations of validity

T. Parent. I shall explain these steps in turn. Let s consider the following passage to illustrate the process:

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

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

Criticizing Arguments

PHI Introduction Lecture 4. An Overview of the Two Branches of Logic

Argument Mapping. Table of Contents. By James Wallace Gray 2/13/2012

LOGICAL THINKING CHAPTER DEDUCTIVE THINKING: THE SYLLOGISM. If we reason it is not because we like to, but because we must.

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

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.

Example Arguments ID1050 Quantitative & Qualitative Reasoning

Mr Vibrating: Yes I did. Man: You didn t Mr Vibrating: I did! Man: You didn t! Mr Vibrating: I m telling you I did! Man: You did not!!

Answers to Practice Problems 6.5

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

Skim the Article to Find its Conclusion and Get a Sense of its Structure

24.09x Guide to Logic and Argumentation

Transition to Quantified Predicate Logic

In a previous lecture, we used Aristotle s syllogisms to emphasize the

Welcome to Philosophy!

A Brief Introduction to Key Terms

Geometry TEST Review Chapter 2 - Logic

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

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

Deccan Education Society s FERGUSSON COLLEGE, PUNE (AUTONOMOUS) SYLLABUS UNDER AUTONOMY FIRST YEAR B.A. LOGIC SEMESTER I

Problems of Philosophy

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

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

FACULTY OF ARTS B.A. Part II Examination,

Philosophy exit exam (Logic: 1-10; Ancient: 11-20; Modern: 21-30; Ethics: 31-40; M&E: 41-50)

Categorical Logic Handout Logic: Spring Sound: Any valid argument with true premises.

A R G U M E N T S I N A C T I O N

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

1. Introduction Formal deductive logic Overview

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

Transcription:

Philosophy 1100: Ethics Topic 1 - Course Introduction: 1. What is Philosophy? 2. What is Ethics? 3. Logic a. Truth b. Arguments c. Validity d. Soundness

What is Philosophy? The Three Fundamental Questions of Philosophy: What is there? What should I do? How can I know? (Metaphysics) (Ethics) (Epistemology) the fourth main branch (Logic) The three main branches of philosophy

What is Philosophy? (there are actually many more specific subfields of philosophy as well... ) feminist philosophy philosophy of mind philosophy of action philosophy of language philosophy of law philosophy of science philosophy of time philosophy of race philosophy of mathematics philosophy of religion

What is Ethics? The Three Main Areas of Ethics: Metaethics - the attempt to discover (i) the meaning of moral claims (ii) the nature of moral facts (if there are any) (iii) how we can know moral facts. our class is on these two Normative Ethics the correct moral principles. Practical Ethics - the attempt to discover - the attempt to discover the answers to certain specific moral questions.

Logic Logic is the study of correct reasoning. In logic, we try to separate the good bits of reasoning (also called inferences, or arguments), from the bad bits. Some concepts from logic that we ll be introducing: statement, truth, argument, validity, soundness.

Statements A statement is a sentence that describes the world as being a certain way. Statements are either true or false.

Statements Some examples of statements: The Earth is round. The Earth is flat. God exists. I hope that God exists. Abortion is wrong. Some people believe that abortion is wrong.

Statements Some examples of sentences that are not statements: What time is it? Close the door, please. Woo Hoo! D oh! (notice that none of these is either true or false)

Truth

WHAT IS TRUTH?

Truth A statement is true when the world actually is the way the statement says the world is. Examples: The statement The Earth is round is true just in case the Earth actually is round. The statement What the teenagers did to the cat was wrong is true just in case what the teenagers did to the cat was in fact wrong.

Arguments An argument is a sequence of statements, the last of which (the conclusion) is supposed to follow from the others (the premises). Sample argument #1: P1. All men are mortal. P2. Socrates is a man. C. Therefore, Socrates is mortal. Sample argument #2: P1. A fetus is a person. P2. If a fetus is a person, then abortion is wrong. C. Therefore, abortion is wrong.

Validity A valid argument is one with the following property: if all of its premises are true, then its conclusion must also be true. In other words: an argument is valid when it is impossible for its premises to be true and its conclusion false. A valid argument does not require that any of the premises or the conclusion actually be true!

Validity Validity Exercises: Sample argument #1: P1. All men are mortal. P2. Socrates is a man. C. Therefore, Socrates is mortal. VALID or INVALID?

Validity Validity Exercises: Sample argument #3: P1. All men are mortal. P2. Boo is not a man. C. Therefore, Boo is not mortal. VALID or INVALID?

Validity Validity Exercises: Sample argument #4: P1. All men are mortal. P2. Boo is not a man. C. Therefore, Boo is mortal. VALID or INVALID?

Validity Validity Exercises: Sample argument #5: P1. All men are mortal. P2. Boo is a man. C. Therefore, Boo is mortal. VALID or INVALID?

Validity Validity Exercises: Sample argument #2: P1. A fetus is a person. P2. If a fetus is a person, then abortion is wrong. C. Therefore, abortion is wrong. VALID or INVALID?

Validity Validity Exercises: Sample argument #6: P1. If a fetus is a person, then abortion is wrong. P2. A fetus is not a person. C. Therefore, abortion is not wrong. VALID or INVALID?

Validity Some common valid argument forms: Modus Ponens P1. P P2. If P, then Q. C. Therefore, Q. Modus Tollens P1. If P, then Q. P2. not-q C. Therefore, not-p. Hypothetical Syllogism P1. If P, then Q. P2. If Q, then R. C. Therefore, if P, then R. Multiple Modus Ponens P1. P P2. If P, then Q. P3. If Q, then R. C. Therefore, R. Multiple Modus Tollens P1. If P, then Q. P2. If Q, then R. P3. not-r C. Therefore, not-p. Categorical Syllogism P1. All A s are B. P2. x is an A. C. Therefore, x is B.

Soundness An argument is sound when (i) it is valid, and (ii) all of its premises are true. So... Let s do a Venn diagram all sound arguments are valid, but not all valid arguments are sound it s much easier for an argument to be valid than it is for it to be sound if we see that an argument is sound, we must accept its conclusion. (not so for validity)

Soundness Some sound arguments: Sample argument #1: P1. All men are mortal. P2. Socrates is a man. C. Therefore, Socrates is mortal. SOUND Sample argument #7: P1. Either Heathwood lives in Denver or he lives in Boulder. P2. Heathwood does not live in Denver. C. Therefore, Heathwood lives in Boulder. SOUND

Logic Let s keep the terminology straight... It is statements that can be true or false. It is arguments that can be valid or invalid, sound or unsound. There is no such thing as a true argument!