Transcript Building Logical Arguments

Building Logical Arguments
Critical Thinking Skills
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Understand and use principles of scientific
investigation
Apply rules of formal and informal logic
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Inductive reasoning
Deductive reasoning
Analyze arguments for soundness of
conclusions
Anatomy of an Argument
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Argument – consists of one more more
premises used to provide support for a
conclusion
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Premises – reasons presented to
persuade someone that a conclusion is
true or probably true.
Assumptions – premises for which no
proof of evidence is offered.
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Often left unstated
Analogy for Understanding
Argument Strength
Conclusion
Premises unrelated to conclusion
Conclusion
Conclusion supported by
many weak premises
Conclusion
Conclusion supported by
single strong premise
Conclusion
Few weak premises fail
To support conclusion
Common Fallacies in Reasoning
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Irrelevant reasons
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Circular reasoning
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If X happens then Y is sure to follow
Weak analogies
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The premise and the conclusion are the same
Slippery slope
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Non sequitur – the conclusion does not follow from
the reason
Similarity between object A and Object B is weak
False dichotomy
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Either-or choice between two outcomes presented
as only possibilities
Final Critical Thinking Skill
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Carefully evaluate the quality of information
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Are there alternative explanations?
Are there contradictory data?
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Evaluating the relative strength of an argument
Evaluating Argument Strength
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What is the conclusion?
What are the premises provided to support the
conclusion?
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3.
Does the conclusion follow from the premises?
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4.
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Are they valid assumptions?
Should they be stated explicitly?
What are the counterarguments?
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6.
Are there any fallacies in the reasoning
What assumptions have been made?
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5.
Are the premises valid? Do they suffer from logical fallacies?
Do they weaken the argument?
Is there any other information omitted from the
argument?
Building Arguments in Your Paper
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The Conclusion
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Your hypothesis is based on the conclusion you
draw after reviewing relevant literature.
Your review of the literature provides the
premises to support your conclusion
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You should look for and provide evidence (if it exists)
that both support and weaken your conclusion
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Inductive reasoning – using the results of a number of
individual studies to support conclusion (specific to general)
Deductive reasoning – using theory (supported empirically)
to make prediction in your specific study (general to
specific)