Argument

Argument: An attempt to give evidence that an idea is true.

• “The form we consider evidence”
• Consists of:
  1. Conclusion: What you’re trying to prove
  2. Premises: Supporting evidence
     • Minimum # to make an argument is 1
       • (an argument with one premise is a syllogism)
  3. Inference: Connects premises
     • Represented by the word “therefore”

Example: “All humans eventually die. I am human. Therefore, I will eventually die.”

• Conclusion: I will eventually die
• Inference: Therefore
• Premises: All humans eventually die \land I am human

Syllogism Example: “I know this student is here because I just saw them”

• Conclusion: Student is here
• Inference: Because
• Premises: I just saw them

Recognizing Arguments: A passage is an argument if it tries to support a statement logically.

• One possible sign of an argument is the use of indicator words like “because” or “since”.

Four Kinds of Passages:

1. Narrative: Series of events
2. Description: Give characteristics of something
   • e.g., “Albert Einstein had white hair”
3. Causal Explanation: Gives cause of something
   • “My car stopped because it ran out of gas” only describes cause, it doesn’t try to argue for it.
4. Argument: Gives evidence to prove an idea is true.

Note: Prof. states that the line between causal explanation and argument is pretty blurry, but still sticks with these older categories and expresses dislike with the new categories in the book…

Examples of Indicator Words:

Diagramming Arguments

Dependent Premises (+): When premises depend on each other to get to a conclusion.

• Example:

I want to graduate in four years + I need 120 units to graduate

---

\downarrow

I need to take an average 30 units per year

Independent Premises: When premises don’t depend on each other to get to a conclusion.

• Example:

x’s fingerprints are on the weapon. x is the heir of the murdered person

\downarrow

x is the murderer

2-Step Argument:

• Example:

My car just broke down on the freeway.

\downarrow

I need a tow (+ I am a AAA member)

\downarrow

I need to call AAA

Exercise 2.2

Prompt: (1) I shouldn’t go home this weekend not only because (2) I have too much studying to do, but also because (3) I can’t afford the trip.

Diagram:

1 2

\downarrow \downarrow

3

Good Arguments v.s. Bad Arguments

Good Argument: Argument that succeeds in proving its conclusion.

• Two Components of a Good Argument:
  1. True Premises
  2. Strong Inference
     • Pretending the premises are true, do they still lead to the conclusion?

Bad Argument: Argument that fails to provide evidence for its conclusion.

Implicit Premises

The implicit premise…

1. … should narrow the logical gap between the stated premise and the conclusion.
2. … shouldn’t commit to more than is necessary.
   • e.g., “Sally can’t go hiking because she has a broken leg” doesn’t mean that “someone with a broken leg can’t move”.