Unit 2: Statements (Lessons 6 & 7)

List the three kinds of self-supporting statements.

1. Self-Reports 2. True or False by Logical Structure 3. True or False by Definition

What are the two types of statements?

1. Self-Supporting Statements 2. Supported Statements.

What is the definition of a statement?

A sentence that has a truth value.

What is a Self-Report?

A statement a person makes about his own thoughts, beliefs or feelings.

What is a Self-Contradiction?

A statement that is always false because of its logical structure.

What is a "tautology"?

A statement that is always true because of its logical structure.

Define a self-supporting statement

A statement whose truth value can be determined from the statement itself. (No outside information is needed to determine if it is true or false.)

What is the Truth Value of a Self-Contradiction?

False because a statement cannot be both true and false at the same time and in the same sense.

Is the following sentence a statement: "Eat your spinach."

No because it is a command and commands do not have a truth value.

Is the following sentence a statement: "The flip will squirt a cruise yesterday in the bright despair."

No because it is a nonsense sentence and does not have a truth value.

Is the following sentence a statement? "What year was Socrates born?"

No because it is a question, and questions do not have a truth value.

What types of sentences are NOT statements?

Questions, Commands and Nonsense Sentences.

Is this the form of a Tautology or a Self-Contradiction: "S is P" and "S is not P"

Self-Contradiction

Is this the form of a Tautology or a Self-Contradiction: "S is P" or "S is not P"

Tautology

What type of self-supporting statement is this: "I think it will rain this afternoon."

This is a "Self-Report".

What type of self-supporting statement is this: "A hat is an article of clothing worn on the feet."

This is a statement that is "False by Definition".

What type of self-supporting statement is this: "The sun is shining and it is not."

This is a statement that is "False by Logical Structure" which is called a "Self-Contradiction".

What type of self-supporting statement is this: "Bachelors are unmarried."

This is a statement that is "True by Definition".

What type of self-supporting statement is this: "The coin will come up heads or not heads."

This is a statement that is "True by Logical Structure" which is called a "Tautology".

What is the Truth Value of a Tautology?

True because it allows for all possibilities.

What is the Truth Value of a Self-Report?

True because we assume that what a person reports about himself is always true.

What are the possible truth values of a statement?

True or False

Is the following sentence a statement: "Shakespeare wrote many plays."

Yes because it has a truth value (true).