21 Common Argument Flaws Flashcards
Ad Hominem
Attacks the person making the argument but says nothing about the argument itself.
False Dichotomy
A false dichotomy is typically used in an argument to force your opponent into an extreme position – by making the assumption that there are only two positions.
A dichotomy is a set of two mutually exclusive, jointly exhaustive alternatives. Dichotomies are typically expressed with the words “either” and “or”, like this: “Either the test is wrong or the program is wrong.”
Confusing Probability for Certainty
Even if something is 99% likely to happen, it does not mean that it will happen.
Could be is not must be.
Percentages v. Quantity
Percentages don’t necessarily reveal quantity and vice versa.
For example, Group A wants a 10% raise and Group B wants a 50% raise. Who will earn more money afterward? Who is asking for more money? We have no way to know based on this information.
Hasty Generalization
Hasty generalization is very similar to sampling error. The difference is that the conclusion is very broad. You cannot make a generalization based on small sample size or based on one or two incidents.
Circular Reasoning
Assuming what you’re trying to prove. The premise is a mere restatement of the conclusion.
“Everything I say is true. This is true because I said it, and everything I say is true.”
Causation Confusions
Whenever the LSAT concludes or assumes that A causes B, 99.9% of the time it’s wrong. They’ll tell you A is correlated with B or that A coincided with B and therefore A caused B. Maybe. That’s just one possible explanation for the correlation. Here are the other 3 possible explanations:
1) B caused A
2) C caused both A and B
3) A and B are merely coincidentally correlated and really something else, X, caused B.
Appeal to Authority
Appeal to Authority, they are claiming that something must be true because it is believed by someone who said to be an “authority” on the subject.
Analogies that really aren’t analogous enough
The two things being analogized lose their relevant similarities and the analogy cannot continue.
We can say attacking LSAT questions is like attacking enemy starships.
But it’s not is it.
Unclearly/Equivocation
The author uses a term (with more than one meaning) inconsistently.
The deliberate use of vague or ambiguous language, with the intent of deceiving others or avoiding commitment to a specific stance.
Tradition Fallacy and Novelty Fallacy
An argument in which a thesis is deemed correct on the basis that it is correlated with some past or present tradition. The appeal takes the form of “this is right because we’ve always done it this way.”
Red Herring
The argument doesn’t address the relevant issue. Rather, it addresses some other issue that is tangential or has nothing to do with the relevant issue but, for some reason, commands your attention.
Relative v. Absolute
A is faster than B, therefore A is fast. Well, not necessarily. A is faster than B in relative terms. It doesn’t imply that A is fast in absolute terms.
Your argument fails therefore the opposite of your conclusion must be true
Be careful of arguments that try to do this. Just because you’ve wrecked someone’s argument, doesn’t mean that you get to conclude the opposite of his conclusion. If I make a crappy argument for going to the movies tonight as opposed to going to a bar or doing any number of things, you can’t just show me why my argument sucks and conclude: therefore we should go to a bar. First of all, there could be other arguments made to support going to the movies. Additionally, you still have the burden of making an argument that we should go to the bar.
Confusing Part v. Whole
You might have heard that the rule is “properties of parts never carry to the whole” or “properties of the whole never carry to its constituent parts.”
