What is Logic ?

• The study of rational argumentation.

Purpose

• identify and understand the difference between good and bad arguments

Inferences

Inductive Inferences

• Reasoning from specific observations to general conclusions
• Based on probability and empirical evidence
• Conclusions are likely but not guaranteed to be true
• Example: Observing that every crow you've seen is black, concluding that all crows are black

Deductive Inferences

• Reasoning from general premises to specific conclusions
• Based on logical necessity
• If premises are true, conclusion must be true
• Example: All humans are mortal; Socrates is human; Therefore, Socrates is mortal

Formal Logic

• Has to do with the "form" or "structure" of arguments
• Consists of:
  • Categorical propositions (statements)
  • Syllogism (it has Major, Minor, and Conclusion)
  • Propositional Logic (it means "to propose", for example "if A then B")
  • Truth tables
  • Predicate Logic (it means "to say something about something", for example "A is B")

Informal Logic

• Has to do with the content or meaning of premises in arguments.
• It's related more with figuring out fallacies in everyday reasoning.
• It includes:
  • Fallacies (mistakes in reasoning)
  • Rhetoric (the art of persuasion)
  • Argumentation theory (the study of how arguments are constructed and evaluated)
  • Critical thinking (the ability to analyze and evaluate arguments)
  • Dialectic (the art of investigating or discussing the truth of opinions)
• Forms the major part of critical thinking

Articulating Disagreement

• Disagreements should be discussed properly and be articulated well enough for us to understand from proper arguments.

What is an Argument?

Good Argument

• One in which the premises gives us a "good" reason to believe in the conclusion

Building Blocks of Arguments

• Premises: Statements that provide support for the conclusion
• Conclusion: The statement that the premises are intended to support
• inferences: The logical connections between premises and conclusion
• It's foundation if laws of logic!

Evaluating Arguments

• neeed to add more exmaples of what kind of argument falls where

Laws of Thought

Law of Identity

• A is A
• Everything is identical to itself

Law of non-contradiction

• Cannot be both true and false at the same time ( like A and not A)
• Nothing can both have the property and lack property at the same time

Law of excluded middle

• Everything is either true or false
• For any particular property, everything either has it or lacks it.