Discussion questions week 5: #3

Chapter six of the Epstein text is based around the concept of compound claims. Much like a compound sentence a compound claim is essentially one statement, but it is gathered from multiple small claims. Two of the most important concepts in understanding compound claims are the contradictory of a claim, and necessary and sufficient conditions.

The first subject, contradictory of a claim, illustrates how to indicate a false compound claim. This concept is defined by the Epstein text as follows: "The contradictory of a claim is one that has the opposite truth-value in all possible circumstances. Sometimes a contradictory is called the negation of a claim." This idea can work in two ways, first we can have the transition from an affirmative phrase to a negative phrase, for example:

A: Mary won't date Brent, or Mary will fall in love with him.

B: Mary will date Brent, or Mary won't fall in love with him. 

In this example the phrase has its meaning changed by switching negatives and positives in the sentence; however in the next example, the opposite is true.

.

A: The house will get cleaned out, or we won't be able to have a party.

B: The house won't get cleaned out, or we will be able to have a party.

In this example we see the meaning is changed to a positive message by the exchanged of the modifiers "will" and "won't". This idea is essential to understanding compound claims and also is an early component chapter seven's concepts.