What kinds of flaws are indicated by absence of evidence questions?
- A lack of evidence for a phenomenon is taken as proof it does not exist
- A flaw in evidence that is attempting to prove a phenomenon is taken as evidence it does not exist
What are the assumptions of appeals and attacks questions?
- They mistakenly assume something is true because an often dubious authority says so
- They mistakenly assume that a personal characteristic is relevant to the substance of that person’s argument
- Evidence trumps character in supporting an argument, ALWAYS!
What are the assumptions inherent in passages of the causal question?
- correlation equals causation
- there are no other causes
- Assumes causality is not reversed (conclusion first, then cause)
What’s the problem in circular reasoning questions?
The conclusion merely restates the premises: it goes nowhere.
What are the comparison flaw patterns?
- Assumes that two things are comparable in all relevant factors
- Assumes that two time periods are comparable in all relevant factors
- What is true of the part is true of the whole, and vice versa.
Sometimes arguments look for flaws that involve assumptions that are either/or. What do these kinds of question say the author of the argument assumes?
The author assumes there are two of potentially several possible ways of doing something.
What’s the flaw to be found in question making necessary assumptions?
- Depends/relies
- They assume something that is required to get a result is enough by itself to guarantee the result
What is the fallacious assumption found in percentages/numbers questions?
- They assume that percentages or ratios are based on the same quantities.
What’s the flaw in shifting meanings questions?
They switch the meaning of a term in the middle of an argument without acknowledging the shift:
“How can we afford to, says the mayor, but I say how can we afford not to?”
- The mayor is talking about the literal cost but the citizen is not: he is talking about the figurative cost
- Look for literal and figurative linguistic differences and polysemic differences
What’s the flaw in Sufficient questions?
- They assume that something guaranteed to get a result is a requirement of the result.
What’s the difference between sufficient conditions and necessary conditions?
S→N, where
S = active, trigger, something that guarantees an outcome (by itself– it is at least enough, but there may be other possible things that could bring about the phenomenon, so it isn’t required).
N = passive, outcome; if not there, and outcome cannot occur. It is required. It has to be more than merely sufficient!
