Presentation on theme: "Chapter 2. Review: What is an argument? God exists. This is a statement, not an argument. God exists. It is as plain as the nose on your face."— Presentation transcript:
Review: What is an argument? God exists. This is a statement, not an argument. God exists. It is as plain as the nose on your face. This is a more emphatic statement, but it is still not an argument. God exists. There are no atheists in foxholes. From a logical standpoint, these two statements are not related.
I think God exists, because I was raised a Baptist. This is not an argument, rather it is an explanation about why someone believes in God. God exists because something had to cause the universe. This is an argument because it has a premise that supports a conclusion.
“Of course tennis players aren’t weak, in fact, no athletes are weak.” This argument is missing a premise. “All true democrats believe in freedom of speech, but there are some Americans who would impose censorship on free expression.” This argument is missing a conclusion. We will talk about this much more in chapter 8.
We talked about deductive arguments in the last chapter. However, there are more things to know about deductive arguments. Validity – if it isn’t possible for the premise(s) to be true and the conclusion to be false. When the premise(s) of an argument are true and the argument is valid, then it is a sound argument. We will talk about this much more in chapter 8, too.
The premises of inductive arguments don’t prove their conclusions; they support them. For example: ◦ “The vast majority of entertainers are extroverts. Dave Letterman is an entertainer. Therefore David Letterman is an extrovert.” Inductive argument. The premises support the conclusion, but they do not attempt to show that the conclusion necessarily follows from the premises.
(A few exercises from 2-5, page of the text) Which of these items are intended to be deductive demonstrations and which are intended to provide inductive support? ◦ 1. No mayten trees are deciduous, and all nondeciduous trees are evergreens. It follows that all mayten trees are evergreens. ◦ 2. Mike must belong to the Bartenders and Beverage Union Local 165, since almost ever Las Vegas bartender does. ◦ 3. I’ve never met a golden retriever with a nasty disposition. I bet there aren’t any. ◦ Please turn to page 56 of your textbook. Identify the premises and conclusion in the first 5 exercises in exercise section 2-3.