SYMBOLIC LOGIC
PREDICATE LOGIC
SEMANTIC METHODS FOR EVALUATING ARGUMENTS
TWO SEMANTIC METHODS
Analogy
English
Interpretation
Instantiation
and
Short Truth Tables
Find a counter-example in
English for the argument form
Pick a universe of discourse
of one or two elements (a, b)
Put the argument into
English through
interpretation
Instantiate the sentences
For example, Ha & Pa
Assign each predicate letter
an English verb or class
Make a short-truth table
of the instantiated sentences
Pick a universe of discourse
such that the constants are
names of individuals in it
Read the short-truth table: all
true premises & a false
conclusion? Invalid