Logical Fallacies

Treating a claim as true because an authority figure - often not an expert - says so.

""A famous footballer says this diet works, so it must.""

Arguing something is true or good because many people believe it.

""Millions of people use this app, so it must be safe.""

Arguing something is right because it has always been done that way.

""We have always marked by hand, so why change?""

Arguing something is good because it is natural, or bad because it is not.

""It is herbal, so it cannot have side effects.""

Attacking the person making an argument instead of the argument itself.

""Why listen to her climate plan? She cannot even keep her garden tidy.""

"You too" - dismissing criticism by pointing out the critic's hypocrisy.

""You say I should eat healthily, but you eat crisps every day!""

Judging a claim by where it came from rather than on its merits.

""That idea came from a tabloid, so it must be wrong.""

Discrediting someone in advance so that anything they say is dismissed.

""Before he speaks, remember he is paid by the oil industry.""

Misrepresenting an opponent's argument to make it easier to attack.

""You want fewer sweets in school? So you want children to never have fun!""

Introducing an irrelevant topic to divert attention from the real issue.

""Why worry about my late homework when there are wars in the world?""

Manipulating feelings instead of offering valid reasons.

""Buy this insurance - think of how your family will suffer without it!""

Deflecting criticism by raising a different wrong done by someone else.

""Our litter problem? What about the litter in the next town?""

Assuming that because B followed A, A caused B.

""I wore my lucky socks and we won, so the socks made us win.""

Claiming one step will inevitably lead to extreme consequences without evidence.

""If we allow phones at lunch, soon nobody will ever talk to each other again.""

Drawing a broad conclusion from too little evidence.

""Two of my neighbours are rude, so everyone in this town is rude.""

Using a personal story in place of solid evidence.

""My grandad smoked and lived to 95, so smoking is not harmful.""

Selecting only the evidence that supports your case and ignoring the rest.

"Quoting the one study that agrees with you out of fifty that do not."

Finding a pattern after the fact in random data, like painting a target around bullet holes.

"Pointing to a cluster of lucky events and calling it proof of a system."

Believing past random events affect future ones.

""Red has come up five times, so black is due next.""

Claiming something is true because it has not been proven false, or vice versa.

""Nobody has proved ghosts do not exist, so they must be real.""

Insisting others disprove your claim instead of supporting it yourself.

""Prove my lucky charm does not work!""

Presenting only two options when more exist.

""You are either with us or against us.""

Using the conclusion as one of the premises (begging the question).

""This book is trustworthy because the book says it is trustworthy.""

Asking a question that contains an unfair built-in assumption.

""Have you stopped cheating at board games?""

Redefining a group to exclude counter-examples.

""No real fan would ever leave a match early.""

Assuming a compromise between two positions must be correct.

""One says 2 + 2 = 4, another says 6, so the answer is 5.""

Continuing something because of what has already been invested in it.

""The film is awful, but we paid for tickets, so we must stay.""

Using a word with two meanings to mislead.

""A feather is light; what is light cannot be dark; so a feather cannot be dark.""

Assuming what is true of the parts is true of the whole.

""Each player is brilliant, so the team will be brilliant.""