TentmakersVA Beach

February 2011

Logical Reasoning & Thinking

LogicOrdered thinking“Logic is the study of right reasons or valid

inferences and the attending fallacies, formal and informal.”

I Corinthians 14:33 – God is a god of order!John 1 – “Logos” is the

order/logic/wisdom/reason of GodGenesis 1:1-2 – God makes order out of chaos

Why Logic Matters in Christianity

Logic helps us live long and prosper in our spiritual walk!

Logic is the basis for exegesis/hermeneutics of the Scripture.

Logic is necessary for presenting reasons/defense for the hope that you have.

Logic will help you connect with different people and different worldviews to evangelize more effectively.

Logic will help you discern between false and sound doctrines.

Why Logic Matters in Christianity

It is the glory of God to conceal a matter; to search out a matter is the glory of kings.

-Proverbs 25:2

God’s Creation, Man’s Discovery

Four Rules of Aristotelian Logic1. Rule of Identity: A is A2. Rule of Non-Contradiction: A is not

(-A)3. Rule of Excluded Middle: Either A

or (-A)4. Rule of Rational Inference

Aristotelian Logic

Inductive & Deductive LogicInductive Deductive

Particular to general General to particular

Particular to particular General to general

Effect to cause Cause to effect

Reasoning after facts Reasoning before facts

Scientific/legal reasoning Philosophical reasoning

Probable conclusion Necessary conclusion

Argument: a collection of related propositions resulting in a conclusion

Proposition: a declarative statement that affirms or denies something

Premise: a proposition that sets forth a reason to draw a conclusion

Conclusion: a proposition derived from the inferences of its premises

Building Blocks

Basic argument in deductive logic that takes the following form:

Syllogism (Deductive)

Premise 1 Premise 2 Conclusion

Premise 1: Only doers of the whole Law are righteous.

Premise 2: Jews do not do the whole Law.Conclusion: Jews are not righteous.

Syllogism (Deductive)

Romans 2:12-13

Romans 2:17-24

Romans 3:9, 23

Gathering and synthesizing evidence/reasons that funnel toward a general conclusion.

Building a Case (Inductive)

Conclusion

Evidence 3

Evidence 2Evidence 1

Acts 2 – Peter’s SermonEvidence 1: Jesus performed signs and

miracles publicly.Evidence 2: God raised Jesus from the dead in

accordance with the Scriptures.Evidence 3: Jesus ascended to heaven to be

glorified in accordance with the Scriptures.Conclusion: “Therefore, let all Israel be

assured of this: God has made this Jesus, whom you crucified, both Lord and Christ.”

Building a Case (Inductive)

Jesus is Lord and Christ!

Acts 2:33-35

Acts 2:23-32

Acts 2:22

Building a Case (Inductive)

Truth: Is the content of the statement accurate in its meaning?

Validity: Does the form of the argument reflect proper steps of reasoning/logic?

An argument can be valid, without necessarily being true.

Truth & Validity

Have to do with “truth” of the argument/statement.

Does the content meaningfully and properly relate to the issue at hand

Aristotle initially identified 13 logical fallacies; the number of fallacies varies based on definition

Logical Fallacies (Informal Fallacies)

Has to do with the definition and context of a word or phrase. By obscuring or changing the definition or context, one can manipulate an argument or confuse a listener.

Ambiguity (Amphiboly) - “I really didn’t like the dance. Young men and women shouldn’t be involved in that.”

Equivocation (word) – “Giving money to the poor is the right thing to do. And since the poor have a right to your money, you should give it before they sue you.”

Equivocation (context) – “He must really be a spiritual guy. When he stubbed his toe, I heard him yell ‘goodness, gracious!’”

Ambiguity & Equivocation

Forms of stereotyping when one uses invalid inductive or deductive logic to draw conclusions.

Whole-to-part & Part-to-whole fallacySweeping generalization (whole-to-part)

“A” has characteristic X, “P” is a part of A, and therefore has characteristic X.

“I went to church and most of the folks I knew were hypocrites. You go to church, so you must be a hypocrite too.”

Hasty generalization (Part-to-whole): If “A” is X, and “B” is X, then anything with attributes

similar to A and B are also X.“I shared my faith with 2 classmates, and they weren’t

open. I guess no one in my class is open!”

Hasty & Sweeping Generalization

Applying a general rule to a specific case, where the rule does not apply.

“Baptism can’t be necessary for salvation. The thief on the cross was not baptized, but Jesus said they would be together in Paradise.”

Accident/Exception

A non-sequitir fallacyIf A, then B. Therefore, if B, then A.“If you are a true Christian, then you will

share your faith. I know people who share their faith, that means they must be true Christians.”

Affirming the Consequent

Making a valid set of propositions centering on a point, only to draw an irrelevant or incorrect conclusion.

“God allows the world to continue the way that it is. God allows people to go on living. God sees all the evil that is going on. God could end everything, but he doesn’t. God must not care about the world.”

Missing the Point

Character assassination; attacking the speaker making the point instead of the point itself

“There has been much debate about whether Mel Gibson’s ‘Passion of the Christ’ is historically accurate. Mel Gibson, alleged to be an alcoholic and anti-Semite, is a devout member of a conservative branch of Catholicism.”

Ad Hominem

Manipulating a point by interjecting an emotionally charged appeal (pity, anger, devotion).

“How can Christians talk about a ‘good’ God? Read the OT accounts of warfare and genocide. In the name of God, the armies of Joshua slaughtered defenseless women and innocent children! They even slaughtered the animals! They took no prisoners and killed defeated soldiers who surely begged and pleaded for their lives!”

Appeal to Emotion

Tries to persuade someone to accept the truth of a point because most people believe it.

“A 1998 poll showed that only 7% of members of the National Academy of Science believed in a personal God. Those people would do well to follow the lead of 93% of their colleagues and adjust their beliefs accordingly.”

Appeal to the People

Deciding a point by referencing an authority figure who agrees with the point

Note that this fallacy occurs when the authority is irrelevant to the point at issue or when the issue resides outside the area of the authority’s expertise.

“Richard Dawkins is a world famous evolutionary biologist who holds the Chair of Public Understanding of Sciences at Oxford University. He does not believe the Bible is a historically reliable document.”

Appeal to Authority

When the conclusion is sneaked into the premises; having already agreed to the premises, the conclusion is inescapable.

“Since religion is a collection of unjustified beliefs, trying to reason with a Christian is pointless. No matter what happens, their point of view is irrational.”

Begging the Question

Describing an opponents view inaccurately, making it easier to criticize and reject.

“Christians who take the Bible literally are ignorant. How can someone believe that the world was made in 6 days, and believe that Jesus will return with a sword in his mouth, and understand the basic facts of nature, biology and evolution?”

Straw Man

Focusing on evidence that supports a point while ignoring other relevant evidence that may contradict it.

“I went to a church for a little while, and a lot of the people that I knew were hypocrites. Clearly, Christianity isn’t something that people can live up to or really take seriously.”

Special Pleading

Diverting the conversation onto a different track and arriving at an unrelated point.

“There has been much debate about the doctrine of infant baptism. One area of study is the Patristic writings. Tertullian, an influential early Christian teacher, argued that baptism was meaningless unless the believer understood the grace of God. Later in life, Tertullian was excommunicated from the church for espousing beliefs about the Holy Spirit that were deemed heretical. Today, disagreement continues between believers about the Holy Spirit and miracles.”

Red Herring

Inaccurately reduces a complex issue into one part of that issue.

“Religion is simply humankind’s way of dealing with anxiety about death.”

Reduction Fallacy

Focuses on the source of a point/issue and argues against the point/issue by attacking the source.

“At the Council of Nicaea, the participants discussed the canon and composition of the Bible. The council was called together by Constantine – a pagan emperor concerned with unifying his empire. Considering the political concerns of Constantine, we should be skeptical of the contents of the Bible.”

Genetic Fallacy

A fallacy based on confusionAn “apples-to-oranges” comparison that

assumes something is part of a category to which it does not really belong.

“Who made God?”

Category Mistake

Analogies are often used in arguments, and a point can be manipulated by offering an analogy that does accurately reflect the issue at hand.

“There are lots of different kinds of cars, but in the end they are all vehicles that get you from point A to point B. In the same way, there are lots of different kinds of religions, and there’s no reason to prefer Christianity over any others, except as a matter of opinion or culture.”

Faulty or Weak Analogy

Also called false dichotomyPresents a limited number of options and

assumes that no other options can exist.“Faith and reason are irreconcilable. Either

you are a person of faith or you are rational.”

False Dilemma

Also called “post hoc”“A” happened before “B”, therefore B

happened because of A.“Christianity is a violent religion. Just look at

the Catholic Church in the Middle Ages and you will find accounts of war, inquisition and execution performed in the name of Christ.”

False Cause

For every right way to think, there is a wrong way to think!

Many Others…

Although Jesus probably existed, reputable Bible scholars do not in general regard the NT (and obviously not the OT) as a reliable record of what actually happened in history, and I shall not consider the Bible further as evidence for any kind of deity. In the farsighted word of Thomas Jefferson…’The day will come when the mystical generation of Jesus…will be classed with the fable of the generation of Minerva in the brain of Jupiter.’”

-Richard Dawkins, “The God Delusion”

Exercise 1

“The claim that I am an atheist because I don’t understand ‘love’ is particularly ironic. I do understand what love is, and that is one of the reasons I can never again be a Christian. Love is not self-denial. Love is not blood and suffering. Love is not murdering your son to appease your own vanity. Love is not hatred or wrath, consigning billions of people to eternal torture because they have offended your fragile ego or disobeyed your rules. Love is not obedience, conformity or submission. It is a counterfeit love that is contingent upon authority, punishment or reward. True love is respect and admiration, compassion and kindness, freely given by a healthy, unafraid human being.”

-Dan Barker, “godless”

Exercise 2

Hebrews 11:1 defines faith as ‘the assurance of things hoped for, the conviction of things not see’. Read in the right way, this passage seems to render faith entirely self-justifying: perhaps the very fact that one believes in something which has not yet come to pass (‘things hoped for’) or for which one has no evidence (‘things not seen’) constitutes evidence for its actuality (‘assurance’). Let’s see how this works: I feel a certain, rather thrilling ‘conviction’ that Nicole Kidman is in love with me. As we have never met, my feeling is my only evidence of her infatuation. I reason thus: my feelings suggest that Nicole and I must have a special, even metaphysical, connection – otherwise, how could I have this feeling in the first place? I decide to set up camp outside her house to make the necessary introductions; clearly, this sort of faith is tricky business.

-Sam Harris, “End of Faith”

Exercise 3

Logic helps us live long and prosper in our spiritual walk!