Building Logical Arguments

1
Building Logical Arguments
2
Critical Thinking Skills

• Understand and use principles of scientific
  investigation
• Apply rules of formal and informal logic
• Inductive reasoning
• Deductive reasoning
• Analyze arguments for soundness of conclusions

3
Anatomy of an Argument

• Argument consists of one more more premises
  used to provide support for a conclusion
• Premises reasons presented to persuade someone
  that a conclusion is true or probably true.
• Assumptions premises for which no proof of
  evidence is offered.
• Often left unstated

4
Analogy for Understanding Argument Strength
5
Common Fallacies in Reasoning

• Irrelevant reasons
• Non sequitur the conclusion does not follow
  from the reason
• Circular reasoning
• The premise and the conclusion are the same
• Slippery slope
• If X happens then Y is sure to follow
• Weak analogies
• Similarity between object A and Object B is weak
• False dichotomy
• Either-or choice between two outcomes presented
  as only possibilities

6
Final Critical Thinking Skill

• Carefully evaluate the quality of information
• Are there alternative explanations?
• Are there contradictory data?
• Evaluating the relative strength of an argument

7
Evaluating Argument Strength

• What is the conclusion?
• What are the premises provided to support the
  conclusion?
• Are the premises valid? Do they suffer from
  logical fallacies?
• Does the conclusion follow from the premises?
• Are there any fallacies in the reasoning
• What assumptions have been made?
• Are they valid assumptions?
• Should they be stated explicitly?
• What are the counterarguments?
• Do they weaken the argument?
• Is there any other information omitted from the
  argument?

8
Building Arguments in Your Paper

• The Conclusion
• 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
• You should look for and provide evidence (if it
  exists) that both support and weaken your
  conclusion
• 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)