An Introduction “[We] let our young men and women go out unarmed, in a day when armor was never so necessary. By teaching them all to read, we have left them at the mercy of the printed word. By the invention of the film and the radio, we have made certain that no aversion to reading shall secure them from the incessant battery of words, words, words. They do not know what the words mean; they do not know how to ward them off or blunt their edge or fling them back; they are a prey to words in their emotions instead of being the masters of them in their intellects. We who were scandalized in 1940 when men were sent to fight armored tanks with rifles, are not scandalized when young men and women are sent into the world to fight massed propaganda with a smattering of "subjects"; and when whole classes and whole nations become hypnotized by the arts of the spell binder, we have the impudence to be astonished. We dole out lip-service to the importance of education--lip- service and, just occasionally, a little grant of money; we postpone the school-leaving age, and plan to build bigger and better schools; the teachers slave conscientiously in and out of school hours; and yet, as I believe, all this devoted effort is largely frustrated, because we have lost the tools of learning, and in their absence can only make a botched and piecemeal job of it.” “ It is here [in teaching of formal logic] that our curriculum shows its first sharp divergence from modern standards. The disrepute into which Formal Logic has fallen is entirely unjustified; and its neglect is the root cause of nearly all those disquieting symptoms which we have noted in the modern intellectual constitution. Logic has been discredited, partly because we have come to suppose that we are conditioned almost entirely by the intuitive and the unconscious. There is no time to argue whether this is true; I will simply observe that to neglect the proper training of the reason is the best possible way to make it true.”
Definitions Reasoning conducted or assessed according to strict principles of validity.
Logic studies reason itself as a tool of knowledge.
Logic is the study of right reason or valid inferences, and the attending fallacies, formal and informal.
Logic means putting your thoughts in order. Definitions Logic is an instrument of human knowledge. As a discipline it involves the study of the science and art of right reasoning that directs the faculty of reason so as to enable one to advance with order, ease, and correctness in the act of reason. Reasons Logic is unavoidable
Logic is undeniable
Logic works
Theological methods build on laws of logic 1. Simple Apprehension
2. Judgement
3. Reasoning Knowledge begins in sense experience
What is it?
Concept
Term
Word
Clear or Unclear Relating concepts
Is it?
Judgement
Proposition
Declarative sentence
True or False Relating propositions
Why is it?
Inductive arguments
Deductive arguments
Valid or Invalid “There are three questions you should habitually ask yourself when writing or speaking, and of others when you are reading or listening to them.”
1) Are the terms all clear and unambiguous?
2) Are the premises all true?
3)Is the reasoning logically valid?
“If the answer to all three these questions is yes, then the conclusion of the argument must be true.” Material Logic
Concerned with the content of arguments. Formal Logic
Concerns the way in which the content is arranged. Fallacy: A mistake in reasoning. Faulty argumentation.
Material fallacies: Mistakes in the content of an argument.
Formal fallacies: Mistakes in the structure of an argument. Fallacies of language
Equivocation: A term is used in more than one sense in an argument.
All laws require lawgivers. Natural laws are laws. Therefore natural laws require a lawgiver. Fallacies of language
Slanting: Use of language assumes value or disvalue of a thing in its description.
Pro-choice vs. “Anti-choice” Pro-life vs. “Anti-Life” Fallacies of language
“Straw man”: Refuting an unfairly weak version of an opponent’s argument.
Everything that exists has a cause. The universe exists. Therefore the universe has a cause.
Refutation: God exists therefore God has a cause Fallacies of Diversion Ad Hominem: An argument addressed to the person rather than the issue.
Poisoning the Well: Since Christopher Hitchens’ had a rather sad and pathetic life his arguments against Christianity cannot be taken seriously.
Genetic Fallacy: I cannot accept your arguments against abortion because you are a man. You are a Christian only because you grew up in Lancaster PA. Fallacies of Diversion Appeal to (illegitimate) authority
Evolution is false because Kirk Cameron says so. Fallacies of Diversion Ad Baculum (appeal to force)
“God is dead,” Nietzsche said “Nietzsche is dead,” God said Fallacies of Diversion Ad Populim (appeal to the masses)
“The notion of a timeless truth is based on an outmoded Greek metaphysics that we moderns have rejected.” Fallacies of Diversion Ad Ignorantiam (appeal to ignorance)
“We know of no natural cause that could have produced that effect, therefore it must have been a miracle.” Fallacies of Oversimplification Quoting out of Context
In Jeremiah 11:29 God says “For I know the plans I have for you,” declares the LORD, “plans to prosper you and not to harm you, plans to give you hope and a future.” Therefore every Christian can expect to be prosperous in this life Fallacies of Oversimplification Composition
The 9/11 bombers were Muslims therefore Islam is a violent religion. Fallacies of Argumentation Begging the question
All the precepts of the Bible are true (Why?)
Because they are the word of God (How do you know?)
Because Jesus said so (How do you know he’s truthful)
Because he is God’s son (How do you know he is?)
Because the Bible says so.
How is the married woman able to plan schooling or commit herself to a career as long as her life is constantly open to unplanned pregnancy. Fallacies of Argumentation Contradictory Premises
Even if the fetus is a person, I still believe in abortion because I believe in every person’s right to control her body.
It is universally true that there are no universal truths. Fallacies of Argumentation Complex Question
Does Jesus know the time of the second coming?
Who made God? Fallacies of Induction Hasty generalization
The New Atheists are all full of vitriol. Look at Richard Dawkins, Daniel Dennett and Christopher Hitchens. Fallacies of Induction Post Hoc Ergo Procter Hoc
I must be called to this new pastorate because after I accepted it we sold our house.
After couples convert to Christianity their marriages are restored, therefore conversion brings restoration in marriage Fallacies of Induction Argument from Silence
The Gospel of John must have been written before A.D.70 since it does not mention the destruction of the temple. Procedural Fallacies Ignoring the Argument
Protestant “refutes” the Catholic argument for papal infallibility by pointing out the corrupt Borgia popes (confusing moral infallibility and doctrinal infallibility) but ignores the Catholic arguments from tradition and authority of the church. Procedural Fallacies Answering Another Argument than the One Given
“Slavery is morally wrong, it violates a basic human right.”
“Oh, I know that argument. You think it’s always wrong to have a slave, because it’s harmful, and makes for suffering and misery. But it doesn’t. Sometimes people are happier as slaves. Sometimes the relationship is a good one. And sometimes slavery is the only other alternative to death. Your argument ignores special cases like that.” Metaphysical Fallacies Reductionism
Religion is nothing but an emotional crutch.
“Why are you so surprised? said the retired star to the children. “Because in our world a star is only a big ball of gas.” “Even in your world that is not what a star is, only what it is made of.” Anthony Weston, A Rulebook for Arguments
Norman Geisler & Ronald M. Brooks, Come Let Us Reason: An Introduction to Logical Thinking.
Scott M. Sullivan, An Introduction to Traditional Logic: Classic Reasoning for Contemporary Minds
Peter Kreeft, Socratic Logic.