PHIL 1115 Lecture Notes - Lecture 3: Formal Grammar, Chardonnay, First-Order Logic

• School: Northeastern University
• Department: Philosophy
• Course: PHIL 1115
• Professor: Branden Fitelson

Document Summary

Sentential form- each basic (atomic) sentence is replaced with a single letter. Basic sentence- a sentence that doesn"t have any sentence as a proper part. It isn"t the case that brendan is 6 ft tall. Showing that an argument fits a valid form means that it is universally valid, but showing that an argument fits and invalid form does not mean that is it necessarily false. Every invalid form has some valid instances. It is valid because it is logically impossible that both p and not p (never can be true, self contradictory) is true and q is false. Logically unsound because the premise can"t be true. It is valid because it is logically impossible that both p is true and either q or not q (can never be false) is false. Logically sounds but not really useful because the conclusion is a logical. Not all absolutely valid arguments have valid sentential forms. Still an invalid sentential form (p. q.