A Good Argument Has to Pass Two Tests
For an argument to persuade you, it has to pass two tests at once:
Test one: Are the premises true? (The reasons you give have to be facts.)
Test two: Does the reasoning hold up? (Even if the reasons are true, do they actually lead to this conclusion?)
Only when both tests are passed is it a good argument. Fail either one, and the conclusion isn't reliable.
First Way to Crash: The Premise Is False
Sometimes the reasoning is flawless, but the reason itself is wrong.
Example: "All mushrooms are edible; this is a mushroom; so this one is edible."
The form of the reasoning is perfectly correct, but the first premise is false—many mushrooms are poisonous. Once a premise is false, the conclusion is dangerous.
Second Way to Crash: The Reasoning Doesn't Hold Up
The other situation is this: the reasons are all true, but they simply can't support this conclusion.
Example: "He's very rich (true), so his character must be good."
Being rich is a fact, but "rich" doesn't lead to "good character"—the two aren't necessarily connected. The premise is true, yet the reasoning collapses.
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Which two conditions must a "good argument" satisfy at the same time?
答案：The premises are true, and the reasoning holds up
A good argument = true premises + sound reasoning, both tests passed. How many premises, how confidently it's stated, how many agree, or how smooth the sentences are can't make an argument good.
"All birds can fly; penguins are birds; so penguins can fly." Where does this argument go wrong?
答案：False premise: not all birds can fly
The form of reasoning is fine (general rule applied to a specific case); the flaw is the false first premise "all birds can fly" (penguins and ostriches can't fly). A false premise leads to a wrong conclusion.
"She's tall, so she must be good at basketball." Where does this argument go wrong?
答案：The reasoning doesn't hold: being tall doesn't lead to being good at basketball
"She's tall" can be true (true premise), but it doesn't lead to "good at basketball"—the two aren't necessarily connected. The reasoning test is where it collapses.
True or false: as long as an argument's form of reasoning is correct, its conclusion is bound to be correct.
答案：False
The form of reasoning can be right, but if the premises are false the conclusion can still be wrong. A reliable conclusion needs both tests passed: true premises + sound reasoning.
The two conditions of a good argument: one is that the premises are true; the other is that the ____ holds up.
答案：reasoning
A good argument = true premises + sound reasoning. Meeting only one—true premises with collapsed reasoning, or sound reasoning with false premises—isn't a good argument.
True or false: when you find an argument unreliable, first figuring out whether it's a "false premise" or "the reasoning doesn't reach the conclusion" makes your rebuttal more targeted.
答案：True
Right—seeing which test the real problem lies in lets you rebut precisely: for a false premise, point out the factual error; for collapsed reasoning, point out that the reasons can't support the conclusion.