Argument Reconstruction

This lecture covers basic argument reconstruction.

Textbook:
Bowell, Tracy, and Gary Kemp. Critical Thinking : A Concise Guide, Routledge, 2014. ProQuest Ebook Central, https://ebookcentral.proquest.com/lib....

Argument Reconstruction
• Defusing rhetoric – removing charged or unhelpful rhetoric
• Logical streamlining – restating arguments with logical operators
• Make Implicit premises explicit – state hidden opinions
o Implicit premises are usually connecting premises.
 Usually, conditionals or generalizations.
• Remove any irrelevant statements
• Remove ambiguity and vagueness or restate them as specifically as possible
o Ambiguity is a premise that is unclear
o Vagueness relates to words or groups of words with no precise meaning (fat, big, small, heavy, light)
• Quantify any generalizations
o Scope of generalizations (Set Theory)
 Cows eat grass vs. brown cows eat grass

Practical Reasoning (Utilitarian Reasoning)
• It is means-ends reasoning focused on getting the maximum value or most good.
o Uses calculations such as expected value to determine the appropriate action.

Expected Joy from going to party
See ex Not see ex
Go to party -10 +5
Not Go 0 0

Chance of seeing ex = 50%

Going
(0.5 x -10) + (0.5 x 5) = -2.5 Expected Joy = -2.5

Not going
(0.5 x 0) + (0.5 x 0) = 0 Expected joy = 0

Not going it the rational choice

• Ideally means-end reasoning ought to be superseded by moral rules.

Arguments
• Some arguments have explanations as conclusions
• Causal generalizations are sometimes confused with mere correlations
• Abduction – inference to best explanation (best guess)