Logic E-Book

Vern S. Poythress

• Herausgeber: Crossway
• Kategorie: Religion und Spiritualität
• Sprache: Englisch

Seitenzahl: 1231

Veröffentlichungsjahr: 2013

Beschreibung

For the well-rounded Christian looking to improve their critical thinking skills, here is an accessible introduction to the study of logic (parts 1 & 2) as well as an in-depth treatment of the discipline (parts 3 & 4) from a professor with 6 academic degrees and over 30 years experience teaching. Questions for further reflection are included at the end of each chapter as well as helpful diagrams and charts that are appropriate for use in high school, home school, college, and graduate-level classrooms. Overall, Vern Poythress has undertaken a radical recasting of the study of logic in this revolutionary work from a Christian worldview.

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“Each of Vern Poythress’s books has been, in my judgment, the best book on its particular subject.”

John Frame, Professor of Systematic Theology and Philosophy, Reformed Theological Seminary, Orlando

“Every new item that Vern Poythress writes is thoughtful, creative, and worth reading.”

C. John Collins, Professor of Old Testament, Covenant Theological Seminary

Logic: A God-Centered Approach to the Foundation of Western Thought

Copyright © 2013 by Vern Sheridan Poythress

Published by Crossway                      1300 Crescent Street                      Wheaton, Illinois 60187

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical, photocopy, recording, or otherwise, without the prior permission of the publisher, except as provided for by USA copyright law. Crossway® is a registered trademark in the United States of America.

Cover design: Matt Naylor

First printing 2013

Printed in the United States of America

Except for appendix F5, all Scripture quotations are from the ESV® (The Holy Bible, English Standard Version®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. 2011 Text Edition. Used by permission. All rights reserved.

All Scripture references in appendix F5 are taken from The Holy Bible, New International Version®, NIV®. Copyright © 1973, 1978, 1984 by Biblica, Inc.™ Used by permission. All rights reserved worldwide.

All emphases in Scripture quotations have been added by the author.

Trade paperback ISBN: 978-1-4335-3229-0 PDF ISBN: 978-1-4335-3230-6 Mobipocket ISBN: 978-1-4335-3231-3 ePub ISBN: 978-1-4335-3232-0

Library of Congress Cataloging-in-Publication Data

Poythress, Vern S.

Logic : a God-centered approach to the foundation of western thought / Vern Sheridan Poythress.

     p. cm.

Includes bibliographical references and index.

ISBN 978-1-4335-3229-0

1. Logic. 2. Faith and reason. I. Title.

BC101.P69         2013

160—dc232012035512

Crossway is a publishing ministry of Good News Publishers.

Contents

Tables and Illustrations

Symbols Used in Parts II–IV

Preface

Part I: Elementary Logic

Part I.A: Introducing Logic and Argument

1 Logic in Tension

2 Why Study Logic?

3 What Do We Trust?

4 Formal Logic

5 Inductive Logic

6 The Importance of Formal Logic

Part I.B: God in Logic

7 Logic Revealing God

8 Logic as Personal

9 Logic within Language

10 Suppressing the Truth

11 Logic and the Trinity

12 The Absoluteness of God

13 Logic and Necessity

14 Transcendence and Immanence

15 Reflections on the Mediation of Human Knowledge of Logic

16 Fallacies and God

Part I.C: The Problem of Classification

17 Analogy

18 Unity and Diversity

19 Stability of Meaning

20 Form and Meaning

21 Context for Meaning

22 Persons and Logic

23 Logic and Religious Antithesis

24 Theistic Proofs

25 Rethinking Western Thought

Part I.D: Aristotelian Syllogisms

26 Theistic Foundations for a Syllogism

27 Venn Diagrams

28 Syllogisms of the First Figure

29 Checking Validity by Venn Diagrams

Part II: Aspects of Propositional Logic

Part II.A: Truth in Logic

30 Truth in Logic: Truth Functions

31 Divine Origin of Logical Functions

32 Complex Expressions

Part II.B: Perspectives on Truth in Logic

33 Venn Diagrams for Truth Functions

34 Other Representations of Logical Truth and Falsehood

35 Boolean Algebra

36 Truth-functional Equivalence

37 Harmony in Truth

38 Perspectives on Truth Functions

Part II.C: Propositional Logic

39 Introducing Propositional Logic

40 Axioms of Propositional Logic

41 Alternative Axioms

42 Dispensing with Axioms

43 Perspectives on Propositional Logic

44 Soundness and Completeness of Propositional Logic

45 Imitations of Transcendence

Part III: Enriching Logic

Part III.A: Predicate Logic

46 Introducing Predicate Logic

47 Theistic Foundations for Predicates

Part III.B: Quantification

48 Quantification

49 The Theistic Foundation for Quantification

50 Axioms and Deductions for Quantification

51 Soundness of Quantification

Part III.C: Including Equality and Functions

52 Equality

53 Functions

Part III.D: Introducing Formal Systems

54 Troubles in Mathematics

55 Axiomatizing Mathematics

56 Studying Proofs

57 Theistic Foundations for Proof Theory

58 A Computational Perspective

59 Theistic Foundations of Computation

60 Models

61 Theistic Foundations for Models

Part III.E: Special Logics and More Enriched Logics

62 Higher-order Quantification

63 Multivalued Logic

64 Intuitionistic Logic

65 Modal Logic

66 Theistic Foundations for Modal Logic

67 Models for Modal Logic

68 Conclusion

Part IV: Supplements

Part IV.A: Supplements to Elementary Logic

A1 Antinomies with Sets: The Set of All Sets and Russell’s Paradox

A2 Deriving Syllogisms of the First Figure

A3 Syllogisms of the Second Figure

A4 Syllogisms of the Third and Fourth Figures

Part IV.B: Supplementary Proofs for Propositional Logic

B1 Some Proofs for Boolean Algebra

B2 Deriving Whitehead and Russell’s Axioms

B3 Practice in Proofs

B4 The Rule of Replacement

B5 Reasoning toward the Completeness of Propositional Logic

Part IV.C: Proofs for Quantification

C1 Deductions of Rules for Quantification

C2 Natural Deduction of Syllogisms

Part IV.D: Proofs for Formal Systems

D1 Introducing Gödel’s First Incompleteness Theorem

D2 Simple Proofs within a Formal System

D3 Deriving Natural Deduction and the Associative Axiom

D4 Helping Lemmas

Part IV.E: Other Proofs

E1 The Halting Problem for Computer Programs

E2 Diagonalization

Part IV.F: Philosophy and Logic

F1 Kantian Subjectivism

F2 The Role of Logic in Philosophy

F3 A View of Modern Logic

F4 Modal Ontological Argument

F5 Reforming Ontology and Logic

Bibliography

Tables and Illustrations

Tables

27.1a:

Imaging the Father-Son Relationship

27.1b:

An Image of the Holy Spirit

27.1c:

Imaging Trinitarian Relationships

30.1:

Truth Table for Logical “Or” (

∨

)

30.2:

Truth Table for Logical “Not” (~)

30.3:

Truth Table for Logical “And” (

∧

)

30.4:

Truth Table for Logical (“Material”) Implication (

⊃

)

32.1:

Calculating Truth Values

32.2a:

All Possible Combinations of Truth Values for

p

,

q

, and

r

32.2b:

All Possible Combinations for

p

,

q

, and

r

Plus Compounds

32.2c:

All Possible Combinations for

p

,

q

, and

r

Plus Compounds, with Calculations

32.3a:

Calculating the Truth Value of ~(~

p

∨

~

q

)

32.3b:

Calculating the Truth Value of ~(~

p

∨

~

q

) for All Possibilities

36.1:

Truth Table for Truth-functional Equivalence

39.1:

Truth Table for ~

p

∨

p

41.1:

Truth Table for the Sheffer Stroke (|)

43.1:

Truth Values of (

p

∨

p

)

⊃

p

43.2:

Truth Values for (

p

∨

(

q

∨

r

))

⊃

(

q

∨

(

p

∨

r

))

63.1:

Truth Table for Kleene’s Three-valued Logic

B5.1:

Checking a Tautology

E2.1:

One-to-one Matching of Infinite Sets

E2.2:

Matching Even Numbers with Whole Numbers

E2.3:

A List of Rational Numbers (with Duplicates)

E2.4:

Rational Numbers with Duplicates Eliminated

E2.5:

Enumerating the Rationals

E2.6:

Trying to Enumerate Real Numbers

E2.7:

Real Numbers with a Diagonal

E2.8:

Diagonalization with Gödel Numbers

E2.9:

Diagonalizing for a Power Set

Illustrations

14.1:

Frame’s Square on Transcendence and Immanence

14.2:

Frame’s Square: Summary of Christian and Non-Christian Views of Logic

27.1:

Dogs and Animals

27.2:

All Dogs Are Animals

27.3:

All Collies Are Dogs

27.4:

Therefore, All Collies Are Animals

27.5:

Venn Diagram for Dogs and Animals

27.6:

Venn Diagram for Dogs and Animals

27.7:

Venn Diagram for Dogs and Animals, with Shading

27.8:

Dogs and Animals Diagram with Empty Region Erased

27.9:

Venn Diagram for Collies, Dogs, and Animals

27.10:

Collies, Dogs, Animals Diagram, with Cross-outs for Dogs

27.11:

Collies, Dogs, Animals Diagram, with Cross-outs for Colliesand Dogs

27.12:

Venn Diagram for Collies, Dogs, and Animals, with Shading

27.13:

Venn Diagram for Nonanimals

27.14:

Nondogs and Nonanimals

28.1:

Venn Diagram for “No Bs are As”

28.2:

Venn Diagram of the Celarent Syllogism

28.3:

Venn Diagram of the Darii Syllogism

28.4:

Venn Diagram of the Ferio Syllogism

29.1:

All Bs Are As

29.2:

All Bs Are As, No Cs Are Bs

29.3:

Some C May Still Be A

29.4:

Genius, Talent, and Doctors

29.5:

“All Geniuses Are Talented”

29.6:

“Some Doctor Is Talented” (Both Subsections Checked)

29.7:

“Some Doctor Is Talented” (Check Mark on Boundary)

30.1:

Truth Values for (

p

or

q

)

33.1:

Venn Diagram of Conjunction (“And”)

33.2:

Venn Diagram of Conjunction (“Or”)

33.3:

Venn Diagram of Negation (“Not”)

33.4:

Venn Diagram of ~

q

33.5:

Venn Diagram of Implication (‘

⊃

’)

33.6:

Alternate Diagram when (

p

⊃

q

)

33.7:

Venn Diagram of

p, q, r

34.1:

Union of Two Sets (

P

∪

Q

)

34.2:

Intersection of Two Sets (

P

∩

Q

)

34.3:

Complement (

'

) of Set

A

34.4:

Set Inclusion:

A

⊆

B

34.5:

Set Inclusion:

A

⊆

B

⊆

C

34.6:

A Trellis

34.7:

Trellis Plus Letters

34.8:

The Join (

∨

) and Meet (

∧

) of x and y

35.1:

Binary Operation of Addition

35.2:

Ternary Operation of Addition

35.3:

The Unary Operation of Negation

36.1:

Venn Diagram of Equivalence

38.1:

Venn Diagram for (

p

∧

q

)

⊃

(

p

∨

q

)

38.2:

Venn Diagram for ~

p

and ~

q

43.1:

Venn Diagram of Conjunction (“Or”)

43.2:

Venn Diagram of

p, q, r

44.1:

Soundness and Completeness

53.1:

Illustration of a Function

54.1:

Nonparallels versus One Parallel

67.1:

Nontransitive Accessibility

67.2:

Transitive Accessibility

67.3:

Symmetric Accessibility

67.4:

Reflexive Accessibility

A1.1:

A Hierarchy of Categories

A3.1:

Venn Diagram of the Baroco Syllogism

A4.1:

Venn Diagram of the Darapti Syllogism

A4.2:

Venn Diagram of the Felapton Syllogism

Symbols Used in Parts II–IV

(Listed in the order in which they are introduced; the symbols , ∨, ∧, and | each have two different usages.)

Symbol

Stands for

Introduced on page

“it is the case”

230

∨

logical “or” (disjunction)

235

~ (or ¬)

logical “not” (negation)

236

∧

logical “and” (conjunction)

237

⊃

(or

→

or

⇒

)

logical (“material”) implication

238

{

a

,

b

,

c

, … }

the set with members

a

,

b

,

c

, …

261

∪

union of two sets

262

∈

“is a member of” (for a member of a set)

262

∩

intersection of two sets

262

'

complement of a set

263

⊆

set inclusion

264

∨

join (in the context of a lattice or a partially ordered set)

267

∧

meet (in the context of a lattice or a partially ordered set)

267

*

a binary operation (in the context of abstract algebra)

272

⊕

an addition-like operation (in the context of Boolean algebra)

274

⊗

a multiplication-like operation (in the context of Boolean algebra)

275

a negation-like operation (in the context of Boolean algebra)

276

≡

or

↔

truth-functional (“material”) equivalence

281

|

Sheffer stroke (logical incompatibility)

322

∀

all

376

∃

existential quantifier (“there exists”)

378

φ

an arbitrary propositional function

396

equality

404

satisfies (in model theory)

458

◊

possibility (in modal logic)

494

□

necessity (in modal logic)

494

|

“such that” (in the context of defining members of a set)

526

in proof theory, “it is provable that” (on the basis of the propositions that

precede

the symbol )

600

Preface

In this book we explore elementary parts of logic and neighboring fields. Part I of the book lays the foundation. In parts II and III we look at further developments in the nineteenth and twentieth centuries. These later developments have affected people’s views of logic as a whole. But not all readers will be equally interested in them. I have placed the discussion of Christian foundations for logic at an early point, in part I, so that people may access it without worrying about technical details. Some readers may content themselves just with part I. Parts I.A–I.C provide the basic discussion of Christian foundations. Part I.D illustrates how these Christian foundations influence our view of Aristotelian syllogisms, which were the earliest and longest lasting form of formal logic.

Logic can be studied without considering the history of philosophy and its interaction with logic. But, for those interested, I have included in appendices F1–F5 some indications of how the nature of logic affects philosophy.

Fully appreciating modern logic involves understanding its interfaces with neighboring fields of study: rhetoric, analytic philosophy, set theory, proof theory, computation theory, abstract algebra, model theory. These fields have experienced extensive development in the twentieth century. One book or even several books cannot begin to cover them. So we have made only a beginning. In addition, logic has a rich and fascinating history.1 I regret that I can mention only a few pieces of history in passing.

I have received help from many sources, both direct and indirect. I thank the Lord, the almighty God, the Creator of heaven and earth, who has given me life and breath and every truth and insight that I have received. He has redeemed me from the pit through Christ my Savior, and set me on the path of eternal life. To him I give all the glory.

I owe a debt also to many human beings, living and dead, to whom God has given truth and insight through his common grace or special grace. I thank my wife, who has borne with the production of this book and has helped in editing it. I want to recognize Kenneth Pike, Edmund P. Clowney, and John Frame, whose insights gave me many of the tools that I have used in undertaking a Christian analysis of logic. I appreciate Cornelius Van Til, who boldly stressed the distinctiveness of a Christian approach to logic, and D. H. Th. Vollenhoven, who wrote about the necessity for a Christian logic.2 These two men built upon Augustine, who understood the radical absoluteness of God; John Calvin, who vigorously articulated the Creator-creature distinction; and Abraham Kuyper, who proclaimed the lordship of Christ over every sector of life and over every field of academic study.

Then there are those who have worked on logic and neighboring areas: the Sophists, Socrates, Plato, Aristotle, Euclid; and in modern times János Bolyai, Nikolai Lobachevsky, George Boole, Gottlob Frege, Charles S. Peirce, Alfred North Whitehead, Bertrand Russell, Kurt Gödel, David Hilbert, Alan Turing, Alonzo Church, Stephen Kleene, and Alfred Tarski, to name a few. Among them I may also list Hilary Putnam and Saul Kripke, who were my teachers in logic, and Garrett Birkhoff, my advisor and mentor in abstract algebra. I have not always agreed with them, but the world has been blessed by the positive insights that they have contributed through common grace.

I appreciate input given in a book review essay: Calvin Jongsma, “Poythress’s Trinitarian Logic: A Review Essay,” Pro Rege 42/4 (June 2014): 6–15. With this essay in view, I have endeavored to make improvements and clarifications in this new printing. In addition to making minor corrections, I came to agree with Dr. Jongsma that it is better always to use the standard expression “if and only if” when this is what is meant; and I have clarified the meaning of soundness and the two senses of “completeness,” to which the essay drew attention (see pp. 346–347, 400, 402, 423).

1 “Logic, History of,” Encyclopedia of Philosophy, 2nd ed., ed. Donald M. Borchert, 10 vols. (Detroit/New York/San Francisco/ . . . : Thomson Gale, 2006), 5:397–484.

2 Dirk Hendrik Theodoor Vollenhoven, De noodzakelijkheid eener christelijke logica (Amsterdam: H. J. Paris, 1932); see also Vollenhoven, “Hoofdlijnen der logica,” Philosophia Reformata 13 (1948): 59–118.

Part I

Elementary Logic

We develop a Christian approach to logic. In part I, where we consider elementary logic, no special symbols are needed. Our discussion focuses on traditional classical logic, leaving until parts II and III developments in the nineteenth and twentieth centuries.

Part I.A

Introducing Logic and Argument

Chapter 1

Logic in Tension

In the original Star Trek TV series, the characters Spock and Leonard McCoy are opposites. Spock is logical; McCoy is passionate. Spock is cold; McCoy is hot. The contrast raises lots of questions. How does logic fit in with our humanity? Is logic opposite to emotion? What should we be like as human beings—logical or emotional or both?

Logic and Humanity

The Star Trek series gained popularity not only because it had entertaining plots but also because it laid out in narrative form some of the big questions about man and his relation to the cosmos. Who are we? What is the meaning of life? What is the cosmic purpose of humanity? Why do logic and emotion struggle within us?

Viewers’ reactions to Spock reveal different attitudes toward logic. To some people, Spock’s logic is an ideal. To others, he may be either admirable or pitiable, but he lacks something. The creators of the show make their own comment by revealing that, while McCoy is human, Spock is the offspring from a Vulcan father and a human mother. He is only half human. A deeper look at Spock reveals further complexity: though Spock endeavors to follow logic, he sometimes struggles with inner emotions because of his human side. Does this fictional portrayal hint that logic is not enough?

What about us? How do we relate to logic? Does it appeal to us? Or do we feel that by itself it is too “cold”?

Some people are more logical, some more emotional. Some people think that we have problems because we are not logical enough. Others think that we are much too logical. In their view, devotion to logic creates difficulties, and we ought to move beyond logic to something else—to nature or mysticism or art. Science, in the minds of some, is driven by logic and by a tightly defined, cold rationality. Human beings in their full personality are driven by warmth: they have desires and emotions and imagination, which are aptly expressed in the arts, in leisure, in entertainment, and in the humanities. Science, according to this view, is at odds with the humanities and with what is most precious to us.

So what is logic? Is it important? How do we understand its relation to emotion, intuition, and other aspects of human life? How do we use it? Does it have limits?

Christian Logic?

I believe that common conceptions about logic do not provide healthy answers to these questions. We need a new approach to the subject—we need a distinctively Christian approach.

Is there such a thing as a Christian view of logic? We would not be surprised to find a distinctively Christian approach to theology or ethics, because the Bible has much to say about God and ethics. But could there be a distinctively Christian approach to logic? Many people would say no. They would say that logic is what it is, irrespective of religious belief. I think that the reality is more complicated. There is a Christian view of logic. But it will take some time to see why.1

Readers may, if they wish, treat this book as a general introduction to logic. Our discussion does not assume any previous acquaintance with the subject. We try to make the ideas accessible by including simple explanations with each new concept. But the discussion also has pertinence for experts, because we do not take a conventional approach. We develop a distinctively Christian approach. Human thinking about logic needs redeeming. As a result, it will take us some time to come to the point of discussing details that typically become the focus of logic textbooks.

For Further Reflection

What makes the difference between Spock and McCoy so fascinating?

What different reactions are there to Spock as a character, and what do they say about people’s views about logic?

When people think about an ideal for humanity, what role do they assign to logic?

How might human beings deal with the apparent tension between logic and emotion? What implications are there for the nature of our

humanity

?

Why might some people think that a distinctively Christian approach to logic makes no sense?

1 I appreciate the inspiration I have received from Abraham Kuyper, Lectures on Calvinism (Grand Rapids, MI: Eerdmans, 1931), and from Cornelius Van Til, who continued Kuyper’s legacy. Both men counsel us to think and act in all our lives as committed followers of Christ, and to bring our distinctive Christian commitments to bear on every area of life. In principle, Christian distinctiveness applies to logic. But Kuyper says at one point that logic does not need a distinctly Christian reading, and for this concession Cornelius Van Til rightly criticizes him (Abraham Kuyper, Principles of Sacred Theology [Grand Rapids, MI: Eerdmans, 1968], 159–160; Cornelius Van Til, Common Grace and the Gospel [n.l.: Presbyterian & Reformed, 1973], 42–44; Van Til, The Defense of the Faith, 2nd ed. [Philadelphia: Presbyterian & Reformed, 1963], 287–288).

Chapter 2

Why Study Logic?

Why should we bother to study logic? Spock exemplifies one part of its importance. On the one hand, Spock’s rational analysis gives the Star Trek crew valuable advice. On the other hand, we struggle with an apparent conflict between logic and emotion, or even between logic and humanness. We need a remedy.

We can find other reasons for studying logic. Some people find logic intrinsically interesting. For them, it is fun. Others study it for practical purposes. They hope that studying logic can help them sharpen their ability to reason carefully. Practice in logic can help us detect logical errors in reasoning, which have been called logical fallacies.

The Influence of Logic

Logic is important for another, historical reason. Logic has had a profound influence on the whole history of Western thought. In the Western world, the formal study of logic began largely with the Greek philosopher Aristotle—though Aristotle built to some extent on his philosophical predecessors, Socrates and Plato.1 Plato and Aristotle hoped to find deep truths about the nature of the world by careful reasoning. Aristotle’s study of logic tried to codify the most basic forms of reasoning. This codification could then serve as a solid foundation for philosophical investigations trying to answer the big questions about the nature of reality and the meaning of life.

Western philosophy ever since Aristotle’s time has followed in the steps of Plato and Aristotle. Philosophers have reasoned. They have used logic. Up until the nineteenth century, with few exceptions, they built on the foundation of Aristotle’s logic. The nineteenth and twentieth centuries have seen further, more technical developments in logic, which have gone well beyond what Aristotle achieved. But for the most part these developments have enhanced rather than overthrown the classical logic developed by Aristotle. (For more detailed discussion of logic and philosophy, see part IV.F, especially appendix F2. For some alternatives to classical logic, see chapters 63 and 64.)

Logic and philosophy have had a broad influence on intellectual culture in the West. Philosophy has directly influenced intellectual life, because it has seemed to many people to offer the most profound and far-reaching kind of knowledge. Science has taken a leading role in more recent times, but for centuries reasoning in intellectual centers was influenced and guided by ideas from philosophy.

In addition, logic has had indirect influence. People engage in reasoning in every area of serious study, not just in philosophy. In almost every sphere, universities today rely on reasoning—in natural sciences, medicine, historical studies, law, economics, political science, language study, literary analysis, mathematics. Academic work aspires to conduct its reasoning rigorously. And logic is a model for rigor. Reasoning in universities today still has underneath it the foundation for logic that Aristotle laid.

Though Aristotle’s logic functions as a foundation for Western thought, we should not exaggerate its role. In both the past and the present, much influential reasoning takes the form of informal reasoning and does not explicitly invoke Aristotelian logic or any kind of formally organized logic. Appropriately, logicians themselves distinguish between the formal logic that Aristotle developed and the informal logic involved in more ordinary instances of reasoning.2 Yet rigorous formal logic offers an ideal that can still influence what people expect and how people evaluate informal reasoning. Logic has an influence far wider than its core.

Logic has also influenced perceptions about the contrast between rationality on the one hand and emotion, desire, and imagination on the other. The historical movement called the Enlightenment championed reason. But soon people became restless. They sensed that reason was not enough. Reason gave us only half of humanity—or less. The Enlightenment stimulated a reaction, the Romantic movement, which depreciated reason and championed the imaginative, the spontaneous, the natural, and the pre-rational aspects of humanity. Like the opposition between sciences and humanities, the opposition between the Enlightenment and the Romantic movement expresses the contrast between logic and emotion, or between Spock and McCoy. Thus, the contrast between Spock and McCoy has analogues that play out in culture and history.

At the foundation of this cultural opposition lies logic. It feeds into the Enlightenment’s conception of reason, and it shapes the Romantic opposition to the Enlightenment as well, because the opposition defines itself in reaction to reason.

This foundation for Western thought in logic needs to be redone. And that means that the whole of Western thought has to be redone. It is a most serious issue.

Arguments

What do we mean by logic? One textbook on logic defines it as “the analysis and appraisal of arguments.”3 When we hear the word argument, we may picture a situation where two people are having a dispute with each other—perhaps a bitter, heated dispute. They are fighting verbally, each person vigorously defending his own view. But the word argument can be used not only to describe quarrels but to describe any reasoning in support of a conclusion.

Arguments of this kind may crop up in friendly settings. An advertisement for a car may present arguments to persuade you to buy one. The advertisement tells you that its car gives you good gas mileage. It is durable. It has special computerized features to play your favorite songs. It has a luxurious interior. It looks cool. And so on. These are informal arguments in favor of buying the car.

We meet arguments not only when someone else is trying to lay out the desirable features of a product, but when we are quietly trying to decide something for ourselves. For example, Irene may be “arguing with herself” about which college to attend. College A is closer to home. College B has lower tuition. College A is reputed to have a better program in economics. College B has a beautiful rural campus. College A is right in the middle of exciting city life. College B has a larger student body. Irene formulates arguments in her own mind in favor of each of the options. Arguments are useful not only for small purchases, but also for major decisions like choosing a college or deciding what kind of job to pursue.

We also meet arguments in academic settings. A university class may lay out reasoning to reach conclusions in chemistry or in the history of World War I. When a class considers disputed ideas, the class members may study arguments both for and against the ideas. Underneath the particular arguments lies a foundation in logic, which analyzes general principles of argument.

Arguments can help to lead us to a wise conclusion. But they can also lead us astray. For example, a student says, “Either you get an A in the course or you show that you are an idiot.” But might there be a third alternative? The presentation of two extreme alternatives as if they were the only alternatives is called the fallacy of bifurcation. There are other forms of fallacy as well. A fallacy is a kind of argument that may sound plausible but that uses tricks rather than solid reasoning.4 Logic includes the study of various kinds of fallacies. People hope that by studying fallacies they may more easily detect them in the future.

Arguments in the Bible

Arguments occur in the Bible. We should not be surprised, because the Bible describes human life in all its ups and downs. For example, a major argument takes place in 2 Samuel 17:1–14. Absalom, the son of David, has just mounted a rebellion against the kingship of his father David. He has forced David out of Jerusalem, the capital city. But as long as David is alive, Absalom’s own position in power remains in jeopardy. Absalom asks for advice from Ahithophel, who has a reputation for giving shrewd counsel (2 Sam. 16:23). Absalom also consults Hushai, who gives opposite advice. Ahithophel says Absalom should attack David right away with a small force of select troops (17:1). Hushai advises Absalom to wait in order to assemble a large army. Both Ahithophel and Hushai give supporting reasons in favor of their stratagems.

Absalom and his supporters think that Hushai’s advice is better. Hushai’s arguments are convincing; but they lead to disaster. Absalom is killed in the battle that eventually takes place (2 Sam. 18:15). Clearly an argument can be a major turning point in a person’s life, and even in the life of a whole kingdom—in this case, the kingdom of Israel.

The arguments from Ahithophel and Hushai are even more striking because the reader of 2 Samuel receives some information that Absalom and Ahithophel did not know. Hushai is pretending to serve Absalom, but secretly he is loyal to David. In fact, David has earlier told Hushai to go to Absalom and to try to interfere by dissuading Absalom from following Ahithophel’s advice (2 Sam. 15:34). Hushai appears to Absalom to give his advice sincerely, and the arguments that he offers are plausible and attractive. But the reader can infer that Hushai does not believe in these arguments himself. He is acting out a role. Hushai’s arguments therefore have two layers: what he intends Absalom to understand and what he himself understands and intends. In fact, the arguments have a third layer, because God the Lord is active behind the scenes: “For the LORD had ordained to defeat the good counsel of Ahithophel, so that the LORD might bring harm upon Absalom” (17:14).

Arguments can be used to deceive and manipulate. But they can also become part of wise counsel. At one point David has decided to order his men to attack Nabal and kill him. Abigail, Nabal’s wife, comes out and dissuades him with her arguments (1 Sam. 25:23–31). David is persuaded, and blesses Abigail for having kept him back from sin (v. 33). The story has a further happy ending because after Nabal dies—by God’s act rather than David’s—David and Abigail marry (v. 42). Abigail’s arguments have steered David toward righteous action and away from sin.

We meet still further arguments within the Bible, including arguments that address all-important religious decisions. The serpent in Genesis 3 gives arguments to try to induce Adam and Eve to sin. Elijah in 1 Kings 18 gives arguments (and a demonstration) to try to turn the people of Israel away from worshiping Baal and toward worshiping the Lord, the true God of Israel. Since Elijah presents himself as a prophet of God, his arguments claim to be not merely human but also divine. Elijah claims that God is presenting the arguments to Israel through him.

The New Testament indicates that God continues to speak, and it includes arguments to call people to come to Christ for salvation. The apostle Peter presents arguments in his sermon in Acts 2:14–36. Since Peter is an apostle, commissioned by Christ, these arguments also present themselves as divine arguments. The apostle Paul presents arguments in his sermons here and there in Acts. Acts 13:16–41; 14:15–17; and 17:22–31 give examples. In addition, some of the summaries of Paul’s preaching mention argument and reasoning:

And Paul went in, as was his custom, and on three Sabbath days he reasoned with them from the Scriptures, explaining and proving that it was necessary for the Christ to suffer and to rise from the dead, and saying, “This Jesus, whom I proclaim to you, is the Christ.” (Acts 17:3)

So he [Paul] reasoned in the synagogue with the Jews and the devout persons, and in the marketplace every day with those who happened to be there. (Acts 17:17)

And he [Paul] reasoned in the synagogue every Sabbath, and tried to persuade Jews and Greeks. (Acts 18:4)

And he [Paul] entered the synagogue and for three months spoke boldly, reasoning and persuading them about the kingdom of God. (Acts 19:8)

We also hear of arguments within the church when controversies arose:

And after Paul and Barnabas had no small dissension and debate with them, Paul and Barnabas and some of the others were appointed to go up to Jerusalem to the apostles and the elders about this question. (Acts 15:2)

The apostles and the elders were gathered together to consider this matter. And after there had been much debate, Peter stood up . . . (Acts 15:6–7)

In 1 Corinthians 15 Paul presents an extended argument to try to correct wavering in the Corinthian church over the question of whether there will be a future resurrection of the body.

The Bible contains many other types of communication in addition to arguments. It has songs, historical reports, prophecies, and so on. But we can use the idea of argument and persuasion as a perspective on everything the Bible does. In a looser sense, we can say that the whole of the Bible functions as an argument to induce us to change ourselves, our beliefs, and our behavior.5

Clearly, arguments play an important role within the Bible. They also have important roles in modern life. Arguments are important, and so logic as the analysis of argument also has an important role.

For Further Reflection

Is logic important? Why or why not?

How has logic influenced Western thought?

How does logic function in universities?

What kinds of arguments take place in Genesis 18:23–33; 27:5–13; 41:33–40; Exodus 4:1–17; 18:13–27; 2 Samuel 12:1–15; 14:1–24; Job; Acts 2:14–36; 3:12–26; 4:8–12; 7:2–53; 13:16–41; 14:15–17; 15:6–21; 17:22–31; 1 Corinthians 15; Galatians; Colossians; Hebrews; James?

What do you think are the most crucial arguments for human well-being?

Why do good arguments sometimes fail to persuade people?

1 Susanne Bobzien, “Logic, History of: Ancient Logic,” Encyclopedia of Philosophy, 2nd ed., ed. Donald M. Borchert, 10 vols. (Detroit/New York/San Francisco/ . . . : Thomson Gale, 2006), 5:397–401.

2 On the distinction between formal and informal logic, see chapter 4.

3 Harold J. Gensler, Introduction to Logic (London/New York: Routledge, 2002), 1. This definition is picked up in Wikipedia: http://en.wikipedia.org/wiki/Logic, accessed September 11, 2010. Isaac Watts’s book Logic, widely used in an older era, defines logic more broadly: “Logic is the art of using reason well in our enquiries after truth, and the communication of it to others” (Logic; or, the Right Use of Reason in the Enquiry after Truth: With a Variety of Rules to Guard against Error, in the Affairs of Religion and Human Life, as Well as in the Sciences [many editions] [London: Tegg, 1811], 1).

4 A fallacy is “an often plausible argument using false or invalid inference” (Webster’s Ninth New Collegiate Dictionary). See S. Morris Engel, With Good Reason: An Introduction to Informal Fallacies (New York: St. Martin’s, 1982).

5 I owe to John Frame this idea of using argument as a perspective on the whole of the Bible.

Chapter 3

What Do We Trust?

In the discussion above we have introduced the Bible into our thinking about argument. What status does the Bible have?

The Status of the Bible

People have different opinions about the Bible. I believe that the Bible is God’s word, his own speech in written form. What the Bible says, God says. But not everyone agrees.

So on this question we have the opportunity to examine arguments and analyze them. Jesus himself testifies to the authority of the Old Testament (Matt. 5:17–18; John 10:35; Luke 24:44–47). Other parts of the Bible and evidence from outside of the Bible can be drawn into the arguments. The arguments about the Bible have already been presented many times in extended form.1 We do not have space to repeat them here. Rather, we are going to use the Bible to try to understand more deeply the character of arguments and logic.

An approach using the Bible may leave many people uneasy. Why? People may have many reasons, but one reason is that, in the modern world, we are accustomed to examining all claims critically. We use reasoning to sift through claims, and we do not trust anything—including statements within the Bible—until they are sifted.

People have attempted to sift through the Bible in many ways, and as a result we have a lot of disagreement about ideas in the Bible. In the modern world, people do not agree about whether God exists. There are other questions as well, a whole list of them. Is Jesus Christ really the Messiah and Savior promised in the Old Testament? Did Jesus Christ really rise from the dead? Is he the only Savior? Does the Bible give us an accurate picture of who Jesus is and what he did? Does following him lead to trusting in the Bible? Is the Bible God’s word?

Foundations: Divine Instruction versus Autonomy

These questions are all important, and they have led to books full of arguments, both pro and con. Any inquirer may examine them for himself. We could repeat some of these arguments, or add further arguments. But such arguments are for other books. In this book, we are focusing on logic. That is, we are focusing on the very process of analyzing arguments. When an inquirer undertakes to analyze a specific argument, whether about God or about some other issue, he inevitably has in the background of his thought some general principles or ideas about evaluating arguments. In effect, he is relying on logic, even if he is not consciously aware of it.

Now a difficulty arises. There are two radically different ways of understanding logic, not just one. There is the Christian way, and there is the usual modern way, which has also been the dominant way within the history of Western philosophy.2 The Christian way is to listen submissively to the instruction of Jesus Christ, who is the Lord of the universe. The modern way is the way of autonomy, where we treat our own human powers as ultimate when we engage in the process of evaluation.

We can illustrate the difference using an incident from the philosopher Socrates, as recorded in Plato’s dialogue Euthyphro. At a key point Socrates requests, “Tell me what holiness is, no matter whether it is loved by the gods or anything else happens to it.”3 The gods in question are the Greek gods, each of whom is limited in relation to the others, and all of whom are finite. They quarrel with one another; they are not reliable. Given that context, it seems eminently reasonable for Socrates to try to find out the real nature of holiness, independent of what the gods may say. He will reason it through. In the context of later philosophical developments in the Western world, Socrates becomes an emblem for using one’s mind and one’s reasoning powers autonomously. The word autonomy in its etymology means “self-law.” Autonomy means making human judgment and human standards for judgment an ultimate touchstone in one’s life.

In contrast to the way of autonomy we have the way of submitting to divine revelation. But is this way really open to us? The situation with the Greek gods shows the difficulty. So-called revelations from so-called gods may be unreliable. They may be worse—they may be manipulative. Human beings may falsely claim to have revelations in order to gain power and prestige. According to the Bible, evil spirits may come to people and give them deceitful “revelations” (Acts 16:16–18; 2 Thess. 2:9–12).

The reality of such counterfeit revelations does not show that genuine revelation is impossible. The counterfeit is the counterfeit of the genuine. The Bible’s claim is precisely that it is the genuine revelation from the one true God. Is that claim true?

Each person has to decide. He has to decide what he thinks about God, about Jesus Christ, about the resurrection of Jesus Christ, and about the status in the Bible. He may find himself weighing arguments pro and con.

Each person has his own personal history. But in some cases, people start with the account of Jesus Christ given in the Bible in the four Gospels—Matthew, Mark, Luke, John. They find out who Jesus is. They read about what he has done. They see the evidence within the Bible for believing that he rose from the dead. Maybe they hear arguments from others. Somewhere along the line, they may become convinced that Jesus really did rise from the dead, and that this miracle proves his claims. They may also become convicted concerning their own rebellion against God and their need for Christ to save them. They commit themselves to become followers or disciples of Christ.

As part of this process, they see that Christ testifies to the divine authority of the Old Testament, and indirectly to the New Testament, because Christ authoritatively commissioned the apostles as witnesses (Acts 1:8). So their view of the Bible changes. They begin to use the Bible’s instruction rather than autonomous judgment as their ultimate guide. Whether the process is long or short, we can see a marked difference between the beginning and the end: they were formerly in rebellion, and now they have been reconciled to God through Christ.

But according to the Bible no one is neutral in the process. We are all by nature rebels against God and we do not want to submit. The Bible itself indicates that the heart of the difficulty is not in the alleged doubtful character of the evidence presented in the Bible (the evidence for the resurrection of Christ is particularly pertinent), but in the doubtful or rather sinful character of us who read it. Moreover, our sinfulness infects our reasoning, so that we come to the evidence with corrupted standards for judging it. Even if the Bible is genuine, we want to judge it rather than submit to God. We want to remain in charge of our life (autonomy), including the life of reasoning. Our desire for autonomy, and the conception of reasoning that goes with it, need changing. We need to be redeemed by God from our rebellion.

“But,” someone may ask, “if an unbeliever is interacting with the Bible and with the evidence for the resurrection of Christ, is he not engaging in autonomous reasoning? Are you not endorsing autonomy at the beginning, when an unbeliever starts his investigation, only to move beyond it at the end?” No, we are not endorsing autonomous reasoning, either at the beginning or at the end. The Bible makes it clear that such reasoning constitutes a form of rebellion against God. It is sinful.

The Bible indicates that God comes to sinners and changes them, through the power of Christ and the power of his resurrection. Christ was raised to new life physically. People who come to Christ receive new life spiritually. They are “born again,” to use the expression in John 3. Such is the only way to overcome sinful rebellion: “Truly, truly I say to you, unless one is born again he cannot see the kingdom of God” (John 3:3).4

This new birth from God is mysterious, because it happens inside people, and no human being is fully aware of all that is going on (John 3:8). On the level of spiritual reality, any particular individual is either for God or against him. But on the level of conscious perception, the situation can often appear to be mixed. People may find themselves attracted to Jesus and yet unwilling to believe his claims or submit to him. God uses his own word in the process of change (1 Pet. 1:23). God’s power and God’s truth in Jesus overcome and change the autonomous dispositions in a person’s heart. A positive result comes about in spite of autonomous desires, not because of them.

If our thinking about reasoning needs redeeming, we are not going to be able confidently to use reasoning in the way that it has often been understood in the Western tradition. We must have a more reliable foundation. God himself is that foundation. We come to know God through Christ. God instructs us about his ways in the Bible. By loving him and absorbing his instruction, we have hope of coming to a sound understanding of reasoning and logic.

But immediately we confront objections to this kind of approach. Objectors might say that they do not accept the Bible as a trustworthy source of truth. They might present arguments. And we in turn may respond with further arguments. But in this process, we differ not only in the conclusions but in our means for evaluating arguments, because there is more than one possible understanding of reasoning and logic.

Reasoning in a Circle?

Are we engaged in circular reasoning? We are already relying on a particular conception of reasoning and logic when we use arguments to establish our conception of logic. But there is no other way of arguing when the nature of logic itself is at stake. We start with instruction in the Bible, and we use it in order to reform logic. And after our reform, we find that logic is in harmony with the God who is described in the Bible. So what have we really accomplished?

The process is really a spiral rather than a circle, because, by the grace of God, we can learn in the process. But it is also worthwhile to point out that when we come to consider the ultimate foundations for thought and the ultimate foundations for human life, everyone is moving in a circle of some kind.5

Autonomy is a circle. Socratic reasoning assumes autonomy at the beginning, and in the end it will develop an autonomously shaped idea of holiness—or justice or goodness or whatever else is the topic of discussion. The typical university program of instruction assumes autonomy at the beginning, and naturally it ends there as well. It appeals to autonomy to establish autonomy. But autonomy is a fruitless circle. In actuality, we are human beings and not gods. We have to rely on other people and on a lot of assumptions, but we typically do not notice it. We do not worry about it.

Should we worry? If we were all naturally good and naturally healthy in our reasoning and in our assumptions, we might conclude that we have no cause for worry. We might also conclude that we can confidently accept the common assumptions made by the people around us, and we can confidently accept what they take to be true. Thoughtful people know better. Why do we grow suspicious?

Are we naturally good? Are we naturally rational in a healthy way? The Bible says we are not. We are corrupted by sin and by sinful desires:

. . . you must no longer walk as the Gentiles do, in the futility of their minds. They are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart. They have become callous and have given themselves up to sensuality, greedy to practice every kind of impurity (Eph. 4:17–19).

None is righteous, no, not one;

no one understands;

no one seeks for God.

All have turned aside; together they have become worthless;

no one does good,

not even one. (Rom. 3:10–12)

People could present arguments back and forth, arguing for and against the proposition that human beings are naturally good. But when we undertake to evaluate the arguments, we already have implicit assumptions or presuppositions about whether we are naturally good and sound in our ability to evaluate. The dispositions of our hearts, whether toward sin or toward righteousness, affect our evaluations.6

As we shall see, we covertly rely on God all along, but we suppress the truth about our reliance. The modern university aspires to be radically critical, but it is not at all critical of the widespread assumption of autonomy, nor is it critical of its own rational foundations.

Biblical Teaching

As a background for our work, we need to take into account the overall message of the Bible. The Bible says that there is one God. This God created the whole world and human beings within it (Gen. 1:1–31). Originally, as it came from God’s hand, this world was good (Gen. 1:31). The human beings whom God created were good, and enjoyed his love and his presence. But human beings rebelled against God—they sinned. Ever since, the human race has suffered under the reign of sin, and human sin has had indirect effects on the rest of the world, which human beings were appointed to care for and rule over (Gen. 1:28–30).

God sent the definitive and perfect remedy for sin in the person of his Son, Jesus Christ, who died for our sins and rose to make us right with God. We are to “believe in him who raised from the dead Jesus our Lord, who was delivered up for our trespasses and raised for our justification” (Rom. 4:24–25). By believing in him, we are saved (John 3:16; Acts 10:43; 13:38–39; 16:31; Rom. 10:9–10). Christ was raised from the dead, and now reigns over the whole universe (Eph. 1:20–22). We wait for the full restoration of human beings and the cosmos when Christ returns (Rom. 8:18–23). Thus we have a sequence of core events: creation, fall into sin, redemption through Christ, and future consummation.

What do these events have to do with arguments? The coming of sin contaminates and distorts arguments. Absalom sinned in trying to murder his father David. Hushai used his arguments deceitfully to try to block the consequences of Absalom’s sin. Abigail had to try to persuade David with arguments because David had undertaken a sinful course of action. The arguments in the sermons in Acts try to persuade people to turn from their sins. Arguments can be used for good, but they can also be used for ill. In Acts 13:8, “Elymas the magician . . . opposed them [Paul and Barnabas], seeking to turn the proconsul away from the faith.”

Christ came to redeem us from sin, not merely to redeem us from bad arguments. The overall picture of the effects of sin is large in scope and deep in its implications. But bad arguments are clearly part of the picture. So the central realities of redemption, and the hope for the consummation of redemption in the future, are pertinent to our understanding of argument.

Moreover, Christ’s reign over the universe implies that he is Lord and judge over all, including being Lord over arguments and over logic. It is beneficial for us to submit to him, because he is infinitely wise with the wisdom of God himself (Col. 2:3). But we also have an ethical obligation to submit to him. Our submission should be thorough, and so it should include submitting our thoughts to him in the area of logic. The apostle Paul talks about taking “every thought captive to obey Christ” (2 Cor. 10:5), and in principle this includes thoughts about logic. But does allegiance to Christ actually make a difference in logic, and if so, what difference? That is the remaining question.

Apologetics

The Bible indicates that in our time the human race is divided in two. We all have sinned (Rom. 3:23); we have all rebelled against God. But some people—not all—have had their rebellious hearts changed and renewed, because God has worked in them to save them. They have trusted in Christ to save them from their sin, and have been united to him as their Savior. Within this life, they are not totally free from sin, but in their hearts they have turned to God and have begun to follow Christ (1 Thess. 1:9). Their minds are being renewed (Rom. 12:1–2).

As a result of this renewing work of God, there are two modes of thinking among human beings. There is rebellious thinking, and there is thinking in communion with God, that is, thinking that endeavors to have fellowship with God, to listen to him, and to submit to his instruction, relying on the power of the Holy Spirit. We might call these two kinds of thinking non-Christian thinking and Christian thinking. But the word Christian needs attention. Many people today may think of themselves as Christian because their parents were, or because they have feelings of admiration for Jesus, or because they attend services in a church building whose roots were Christian. All this is merely superficial. If Christianity is nothing more than this, it is fake Christianity. True Christianity is a matter of the heart, not a matter of a name.

We should also say that, historically, much evil has been done by people who claimed to be Christians. Some of them were only fake Christians. Others were genuine Christians but they nevertheless acted in accordance with sin that was still in them. Christians are not necessarily morally better than anyone else. In fact, they may be worse. But through the Holy Spirit they have recognized that they are worse and that they need help. They have come to Christ, and they have begun to change. But they may still have a long way to go. They may still commit terrible sins. Following the way of Christ does not imply that we condone evil deeds done in his name.

In short, even genuine Christians are not perfect in their deeds. Likewise, they are not perfect in their thoughts. Nevertheless, in principle there are two kinds of thinking, the Christian way and the non-Christian way. In terms of fundamental assumptions and commitments, these two ways are at odds with each other. They are antithetical to each other.

Because there are two kinds of thinking, rather than one, communication is a challenge. It is a challenge even when we study logic, because there are two ways of studying logic, the Christian way and the non-Christian way. The Christian way submits to God’s instruction through Christ. We can receive Christ’s instruction because God has caused it to be written down in the Bible. The non-Christian way follows other standards. Those standards may be the standards within some other religion. But most commonly they are standards of autonomy. Everyone simply judges for himself.7

As a result, we need to reckon with people’s allegiances and heart commitments. Within the twentieth century, some Christians have grappled with this difficulty, and presuppositional apologetics has arisen as a result.8 Because presuppositional apologetics aspires to be based on the Bible’s teaching, it disclaims any independent authority. It intends that its ideas and principles be based on the Bible. Presuppositional apologetics articulates how Christians may be fully loyal to Christ and to the Bible’s teaching when they engage in dialogue with non-Christians. We cannot expound presuppositional apologetics at length, so we will be content to summarize.

Simply put, we who are followers of Christ must be consistent with our basic commitment to him. We submit to his instruction in the Bible. We sift human ideas using God as our standard. We know that God is the source of all truth. We know that even those in rebellion against him know him (Rom. 1:20–21) and rely on him (Acts 14:17). We can communicate with them because they are created in the image of God and live in his world. We can talk about any subject we choose, because every area of life reflects God’s presence in the world. We may speak about what the Bible says, because the Bible as God’s word has spiritual power to convict listeners, even when they do not yet agree that it is God’s word (1 Cor. 2:1–5).9

But in our communication with non-Christians we try to make it clear that we do not agree with their fundamental assumptions and fundamental commitments against God. We have presuppositions different from theirs. Because of God’s mercy, non-Christians can know and do know many bits of truth. In fact, they know God (Rom. 1:20–21). But Christians and non-Christians see truth differently, because non-Christians suppress the fact that they are receiving truth from God, and that what they know is found first of all in the mind of God.

These principles apply to the study of logic. We will try to study logic as followers of Christ. In the process, we need to acknowledge that our thinking is distinct from the thinking of non-Christians. We may still invite non-Christians to listen to our thinking. But the issues are clearer if they are aware that Christians and non-Christians have differing presuppositions.

Are Arguments Unspiritual?

Some Christians have imagined that engaging in argument is innately unspiritual. Argument is indeed unspiritual when it is carried out in an unloving or contentious spirit (2 Tim. 2:24–26; Titus 3:10–11). But what about the apostles’ sermons in Acts or the argument that the Bible presents in 1 Corinthians 15? Are they unspiritual? We cannot draw that conclusion without criticizing the apostles and by implication criticizing God himself. No, in these cases argument clearly has a positive, spiritual role. When Peter and Paul spoke as apostles, they acted out of love for God, zeal for God’s truth, and out of love for people who did not know the truth or who were in danger of rejecting it. In addition, God himself empowered them to speak, so that what they spoke was God’s own word (1 Thess. 2:13; 1 Cor. 2:13; 2 Pet. 1:21).

We should note, however, that if people are stubborn, they may reject an argument even when they should be convinced. Even when an apostle is the preacher, it takes the Holy Spirit to soften the hearts of the hearers (Acts 16:14; 2 Cor. 2:15–16; 2 Cor. 4:4–6).

The resistance to God’s message is serious. It is not merely that people may defiantly stop their ears to argument (Acts 7:57). First Corinthians 1:18–31 indicates that the gospel seems “folly” to those who consider themselves wise. How can a criminal death on a cross, which looks like an ignominious defeat, really mean salvation? People also consider the Christian message foolish because it threatens their pride and position. They already have their own standards for evaluating claims; they have their own views of what is wrong with the world and what a reasonable remedy would be like. They have their autonomous standards for evaluating the Christian message.

In sum, argument has an important role not only in human communication but in God’s own speech to us through agents like the apostles Peter and Paul. God himself uses arguments in religious persuasion. But God is also present through the Holy Spirit to bring about inward readiness in a person’s heart, and to bring subjective conviction in response to arguments and other explanations of the truth. Until God changes people’s hearts, they resist the truth of the gospel.10

For Further Reflection

What are the two antithetical basic stances in human life and in human reasoning?

Does the antithesis between two stances in human life make argument between the two impossible? Why or why not?