What is a Fallacy?
Fallacies are defects that weaken arguments.
Hasty Generalization
Making assumptions about a whole group or range of cases based on a sample that is
inadequate (usually because it is atypical or just too small).
Example: "My roommate said her philosophy class was hard, and the one I'm in is
hard, too. All philosophy classes must be hard!"
Hasty Generalization
Post Hoc (false cause)
Assuming that because B comes after A, A caused B.
Example: "President Jones raised taxes, and then the rate of violent crime went
up. Jones is responsible for the rise in crime."
Post Hoc
Slippery Slope (aka "the Camel's nose)
The arguer claims that a sort of chain reaction, usually ending in some dire
consequence, will take place, but there's really not enough evidence for that
assumption.
Example: "Animal experimentation reduces our respect for life. If we don't
respect life, we are likely to be more and more tolerant of violent acts like war and
murder. Soon our society will become a battlefield in which everyone constantly
fears for their lives. It will be the end of civilization. To prevent this terrible
consequence, we should make animal experimentation illegal right now."
Slippery Slope
Weak Analogy
Many arguments rely on an analogy between two or more objects, ideas, or situations. If
the two things that are being compared aren't really alike in the relevant respects, the
analogy is a weak one, and the argument that relies on it commits the fallacy of weak
analogy.
Example: "Guns are like hammers--they're both tools with metal parts that could
be used to kill someone. And yet it would be ridiculous to restrict the purchase of
hammers--so restrictions on purchasing guns are equally ridiculous."
Weak Analogy
Appeal to Authority
Often we add strength to our arguments by referring to respected sources or authorities
and explaining their positions on the issues we're discussing.
Example: "We should abolish the death penalty. Many respected people, such as
actor Guy Handsome, have publicly stated their opposition to it."
Appeal to Authority
Appeal to Pity
The appeal to pity takes place when an arguer tries to get people to accept a conclusion
by making them feel sorry for someone.
Example: "I know the exam is graded based on performance, but you should give
me an A. My cat has been sick, my car broke down, and I've had a cold, so it was
really hard for me to study!"