Logic
Created @March 24, 2022 2:40 PM
Class
Type
Materials
Reviewed
Formal Logic
studies good/bad reasoning and the differences between the two
Rational evaluation of arguments
Deductive Validity: Impossible for argument to have all true premises and a false
conclusion
Non deductive strength: Truth of premises makes the conclusion more probably than
not
VALID → If premises are true the conclusion HAS to be true
If argument contains contradictory premises → valid because you
cannot prove invalidity.
Why does the truth of some arguments guarantee the conclusion?
Either P or Q
Not P
therefore Q
Logic 1
, All arguments of this form are valid
Sentence Connectives
Sentence connectives operate on declarative sentences to form compund or complex
sentences
Declarative sentences: Sentences that can be true or false
Two Place Connectives
Connectives that operate on two sentences at a time
or, because, and, either
One Place Connectives
Connectives that operate on one sentence at a time
It is good that.../It is not the case that...
The meaning of sentence connectives determine argument forms
meaning of sentence connectives → valid form → valid argumet
Truth Functional Connectives
Truth Values of the complex sentences they generate are determined by the truth
values of the simple sentences
Truth Value: A sentence’s being true or false
Logic 2
Created @March 24, 2022 2:40 PM
Class
Type
Materials
Reviewed
Formal Logic
studies good/bad reasoning and the differences between the two
Rational evaluation of arguments
Deductive Validity: Impossible for argument to have all true premises and a false
conclusion
Non deductive strength: Truth of premises makes the conclusion more probably than
not
VALID → If premises are true the conclusion HAS to be true
If argument contains contradictory premises → valid because you
cannot prove invalidity.
Why does the truth of some arguments guarantee the conclusion?
Either P or Q
Not P
therefore Q
Logic 1
, All arguments of this form are valid
Sentence Connectives
Sentence connectives operate on declarative sentences to form compund or complex
sentences
Declarative sentences: Sentences that can be true or false
Two Place Connectives
Connectives that operate on two sentences at a time
or, because, and, either
One Place Connectives
Connectives that operate on one sentence at a time
It is good that.../It is not the case that...
The meaning of sentence connectives determine argument forms
meaning of sentence connectives → valid form → valid argumet
Truth Functional Connectives
Truth Values of the complex sentences they generate are determined by the truth
values of the simple sentences
Truth Value: A sentence’s being true or false
Logic 2
