PHIL2420 Lecture Notes - Lecture 10: Confirmation Bias, False Dilemma, Begging
1 Jun 2018
School
Department
Course
Professor
PHIL 2420
Critical Thinking
May 17, 2018
WEEK 10
Reasoning and Argument 2
Wason Test
• 90% of people get this wrong
• We’re not doing good at logic in the abstract, better in practical context
• Cognitive psychology test based on reasoning with conditionals
o If, then… Then relationship is …
• Deductive reasoning is also present in research reports
Arguing with Conditionals
• Argument
o If P, then Q
o P _______
o Therefore Q
o OR
o If P, then Q
o Not Q
o Therefore, not P
• Common Fallacies
o 1. Denying the antecedent
▪ If Dad makes pizza, then I’ll eat at home
▪ If P is false, therefore not Q
▪ It’s an inference
▪ Dad didn’t make pizza, and you stayed home and ate anyway →
invalid argument
o 2. Affirming the consequent
▪ Newspapers do this
Critical Reasoning
We can use reasoning to analyze and critique arguments.
ANALYSIS – means to clarify arguments
• Identify assumptions, expose strengths/weaknesses in another’s position
Critique – evaluation of the arguments of others
• Strategies
o Exposing fallacious reasoning (ex. affirming consequent)
o Exposing untrue or questionable assumptions (premises can be based on
assumptions that are not valid)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Wason test: 90% of people get this wrong, we"re not doing good at logic in the abstract, better in practical context, cognitive psychology test based on reasoning with conditionals. If, then then relationship is : deductive reasoning is also present in research reports. If p, then q: p ______, therefore q, or, not q, therefore, not p. If p, then q: common fallacies, 1. If dad makes pizza, then i"ll eat at home. It"s an inference: dad didn"t make pizza, and you stayed home and ate anyway invalid argument, 2. We can use reasoning to analyze and critique arguments. Is there a better generalization that preserves original insight: but doesn"t fall prey to the counter-example, valid arguments are the result of the process. Play the devil"s advocate: lawyers just make good arguments even if client is guilty, provide the best argument you can for a position you disagree with.
