Warmth in Giving

An essential skill to develop—particularly if you intend to discuss the truth of your faith with others—is how to understand, evaluate, and present a logical argument. Though it might seem complex and rather intimidating, an argument in logic is really a very simple thing. To have an argument you must make a claim (called the conclusion, or the central point of the argument) and provide support (called premises, or evidence, facts, and reasons) for believing the claim to be true or correct. To have a good argument (logically sound or cogent), your premises must be (1) true, (2) pertinent to your central claim, and (3) sufficient to justify the conclusion.

What Are Fallacies?

A fallacy occurs when a logical argument contains a specific defect. A defect is a mistake in the reasoning process which causes an argument to break down (or fail to adequately support the conclusion). Left unrecognized and uncorrected, that failure leads to a defeated (unsound or not cogent) argument. Bad arguments provide no logical justification for their claims. Thus the person who reasons carefully will attempt to understand and thus avoid committing the common fallacies that serve to shipwreck arguments.


E-R-A-S-E the Fallacies

Various fallacies (errors in reasoning) describe breakdowns in the all-important premise-conclusion relationship. As stated earlier, for the conclusion of an argument to be adequately supported, all premises must be true, and the argument must employ correct reasoning in using them. Here’s a logical checklist to follow that will help you avoid or erase the most common and dangerous fallacies.

1. Premises should solidly Establish the conclusion.

A viable argument provides support that genuinely establishes the argument’s central claim. Thus the careful thinker will be on guard to avoid unwarranted presumption. Good premises are not based on easily challenged assumptions, but instead on those rational elements that supply legitimate proof or evidence for accepting the conclusion. Common fallacies of presumption include Wishful Thinking, Begging the Question, and Complex Question. (See infographic.)

2. Premises should be Relevant to the conclusion.

The premises that do the supporting must be relevant, applicable, and/or pertinent to the conclusion. Thus the student of logic must be on the constant watch for logical irrelevancy. The support should be readily connected to the conclusion in terms of justifying, grounding, and counting in favor of the truth of the conclusion. Typical fallacies of relevance include Red Herring, Straw Man, Missing the Point, Ad Hominem, Appeal to Pity, and Appeal to Force. (See infographic.)

3. Premises should provide Adequate support for the conclusion.

The premises must sufficiently support the conclusion by providing enough evidence. Thus, the watchman on the logical wall must be aware that fallacies provide some support for the conclusion but ultimately not enough. The enough question should also involve queries about number, kind, and weight of support provided for the conclusion. Common fallacies of inadequacy (also called weak induction) include Appeal to Authority, Appeal to Ignorance, and Hasty Generalization.

4. Premises should provide Simple support for the conclusion.

Good premises avoid confusion and provide simple and clear support for the argument’s conclusion. Thus the logic enthusiast seeks to protect simplicity and clarity by eliminating vagueness (being blurry or fuzzy), ambiguity (having multiple meanings), and grammatical error. Thinking, speaking, and writing should reflect an inner logical unity and coherence. Common fallacies of ambiguity include Equivocation and Amphiboly. (See infographic.)

5. Premises that support the conclusion carefully weigh the Equivalence of comparisons.

Logical arguments often appeal to the use of causal connections and analogical relationships. Thus the reflective person will inquire as to whether these connections and relationships are truly equivalent. However, cause-and-effect connections can be difficult to track and analogies are sometimes difficult to weigh so logical mistakes can easily creep in. To be good at logic requires reflection upon categories and comparable relationships. The False Cause and Oversimplified Cause fallacies have premise-conclusion relationships that reflect problematic causal relationships. Whereas the Slippery Slope and False Analogy fallacies reflect breakdowns in comparing analogical relationships.

Logic is an indispensable tool for weighing and evaluating the merit of arguments, and knowing what constitutes a good argument greatly assists a person in discovering a rational and truthful vision of life. Following the logical checklist above can be of great use in attempting to avoid and ERASE those pesky and destructive logical fallacies.

Reflections: Your Turn 
What are the essential features of a logical argument? What characterizes a good argument? Visit Reflections on WordPress to comment with your response.

For a discussion of the fallacies specifically mentioned in this article, see Kenneth Richard Samples, A World of Difference: Putting Christian Truth-Claims to the Worldview Test (Grand Rapids: Baker, 2007), 55–69.



Subjects: Fallacies, Fallacy, Logic

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About The Author

Kenneth R. Samples

I believe deeply that "all truth is God’s truth." That historic affirmation means that when we discover and grasp truth in the world and in life we move closer to its divine Author. This approach relies on the Christian idea of God’s two revelatory books - the metaphorical book of nature and the literal book of Scripture. As an RTB scholar I have a great passion to help people understand and see the truth and relevance of Christianity's truth-claims. My writings and lectures at RTB focus on showing how the great doctrinal truths of the faith (the Trinity, the Incarnation, the Atonement, creation ex nihilo, salvation by grace, etc.) are uniquely compatible with reason. This approach reflects the historic Christian apologetics statement - "faith seeking understanding." I work to help myself and others fulfill Peter's words in 2 Peter 3:18: "But grow in the grace and knowledge of our Lord and Savior Jesus Christ. To him be glory both now and forever! Amen." As an RTB scholar I have a great passion to help people understand and see the truth and relevance of Christianity's truth-claims. • Biography • Resources • Upcoming Events • Promotional Items Kenneth Richard Samples began voraciously studying Christian philosophy and theology when his thirst for purpose found relief in the Bible. He earned his undergraduate degree in philosophy and social science from Concordia University and his MA in theological studies from Talbot School of Theology. For seven years, Kenneth worked as Senior Research Consultant and Correspondence Editor at the Christian Research Institute (CRI) and regularly cohosted the popular call-in radio program, The Bible Answer Man, with Dr. Walter Martin. As a youth, Kenneth wrestled with "unsettling feelings of meaninglessness and boredom," driving him to seek answers to life's big questions. An encounter with Christian philosophy in Mere Christianity by C. S. Lewis led Kenneth to examine the New Testament and "finally believe that Jesus Christ is the divine Son of God, the Lord and Savior of the world." From then on, he pursued an intellectually satisfying faith. Today, as senior research scholar at Reasons to Believe (RTB), Kenneth uses what he's learned to help others find the answers to life's questions. He encourages believers to develop a logically defensible faith and challenges skeptics to engage Christianity at a philosophical level. He is the author of Without a Doubt and A World of Difference, and has contributed to numerous other books, including: Lights in the Sky and Little Green Men, The Cult of the Virgin, and Prophets of the Apocalypse. He has written articles for Christianity Today and The Christian Research Journal, and regularly participates in RTB's podcasts, including Straight Thinking, a podcast dedicated to encouraging Christians to utilize sound reasoning in their apologetics. He also writes for the ministry's daily blog, Today’s New Reason to Believe. An avid speaker and debater, Kenneth has appeared on numerous radio programs such as Voice America Radio, Newsmakers, The Frank Pastore Show, Stand to Reason, White Horse Inn, Talk New York, and Issues Etc., as well as participated in debates and dialogues on topics relating to Christian doctrine and apologetics. He currently lectures for the Master of Arts program in Christian Apologetics at Biola University. Kenneth also teaches adult classes at Christ Reformed Church in Southern California. Over the years Kenneth has held memberships in the American Philosophical Association, the Evangelical Philosophical Society, the Evangelical Theological Society, and the Evangelical Press Association. The son of a decorated World War II veteran, Kenneth is an enthusiastic student of American history, particularly the Civil War and WWII. His favorite Christian thinkers include Athanasius, Augustine, Pascal, and C. S. Lewis. He greatly enjoys the music of the Beatles and is a die-hard Los Angeles Lakers fan. Kenneth lives in Southern California with his wife, Joan, and their three children.

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