Two aspects of Critical Thinking:

 

1. Gathering evidence 
2. Determining whether that evidence supports or undermines as assertion. 

Argument

Declarative Sentence 

Logic

Premise

Conclusion

Indicator Words

Extended Argument

Universal Generalization 

Statistical Generalization

Ambiguity 

Amphiboly

•  ambiguous sentence structure

• can occure when commas are ommited.

Relative Terms

Vagueness

Intensional Definition

Lexical Definition

Stipulative Definition

Precising Definition

Definition Types

• This type of definition reduces the vagueness of a term.
  • "Full-time student" means "student who is carrying a course load of at least twelve units a semester."

Theoretical Definition

Definition Types

• Two senses of theory:
  • general approach to or belief about a subject matter.
  • set of general, but not vague, interrelated claims about the nature of society or the physical world: can be confirmed or disconfirmed.

Persuasive Definitions

Definition Types

• Definitions designed to transfer emotive force, such as approval and disapproval

  • words that refer to the same objects may differ in emotive force

  • must be sensitive to this, because it can sway our acceptance of a conclusion

Syntactic Definition

Definition Types

• Some words do not of intension or extension (and, or, etc.)
• Definition gives grammatical role of term, with examples of contexts of use.
  • Contextual definition: whole sentence is used to show term's use.

Operational Definition

Definition Types

• Especially important for science.
• Fixes meanings by specifying public and repeatable operations, with specific outcomes, to tell whether a term is applicable in a context.

• with suitable instruments, many terms can be defined operationally (meter, blue, acid)

Deductive Argument

• An argument type constructed such that, if all the premises are true, the conclusion cannot be false.

• conclusion puts together or restates information contained implicitly in premises without adding information: this preserves truth of premises.

Valid Argument

• This type of argument is a (correct, successful, or genuine) deductive argument, that is, an argument in which the premisses, if true, guarantee the truth of the conclusion.

Inductive Argument

• An ampliative argument in which the premisses, if true, make it possible that the conclusion is true.
  • Conclusions of this type of argument amplify or expand the information found in the premisses.

Fallacy

(fallacious argument)

• This is an argument in which the premisses provide only very weak support, or no real support, for the conclusion.

Common Types of Inductive Arguments

• conclude something about future based on what happened in the past.

• conclude something about the past on the basis of present evidence.

• generalize on the basis of a sample of observations or experiments.

• conclude something about a particular case on the basis of what usually happens.

• conclude that a further similarity holds on the basis of known similarities between two types of things.

Sound Argument

• A deductive or inductive argument is this, if all the premisses are true are true for that argument.

Indirect Proof

• Type of argument that shows that a contradiction or an obviously false sentence follows deductively from the assumption that the claim to be proved is false.
  • Since a deductive argument with a false conclusion must have at least one false premiss, this method can be used to show that the original assumption that the claim is false is itself false, or that the claim is true.