Logical Fallacies

Situation: 'You can't prove that ghosts don't exist, so they must be real.'

ad ignorantiam

Situation: 'If we allow students to rewrite one quiz, soon they will demand to skip final exams entirely, and the university will collapse.'

Slippery slope fallacy

Situation: 'My opponent suggests we increase spending on public parks, but we all know he was arrested for tax evasion ten years ago.'

Poisoning the well

Situation: 'Of course this weight-loss supplement works; movie star Brad Pitt endorses it!'

False authority

Situation: 'Either we ban all cars immediately, or we surrender completely to catastrophic climate change.'

False dichotomy

Situation: 'Smoking cigarettes is dangerous because cigarettes can kill you, and anything that kills is inherently deadly.'

Circular reasoning

Situation: 'Every time I wash my car, it rains later that day. Washing my car must cause rain.'

False cause

Situation: 'Millions of people believe in astrology, so it must be a valid way to predict personality.'

Bandwagon fallacy

Situation: 'You claim that municipal taxes are too high, but think of the starving children in developing nations who have no homes at all.'

Appeal to worse problems

Situation: 'Since every brick in this building is lightweight, the entire building must be lightweight.'

Fallacy of composition

Situation: 'The government corporation is heavy, so every single employee working there must be physically heavy.'

Fallacy of division

Situation: 'If you don't agree with my economic policy, your business will fail and your family will lose their health insurance.'

Appeal to force or threat

Situation: 'We should adopt this new software framework simply because it was released yesterday and uses the latest paradigm.'

Appeal to novelty

Situation: 'We have always used paper ledgers in this office for fifty years, so we cannot switch to digital databases now.'

Argumentum ad antiquitatem

Situation: 'Natural herbal remedies are always safe and healthy because they come straight from nature, unlike synthetic medicines.'

Appeal to nature

Situation: 'Please do not give me a failing grade; my cat just ran away and I have been feeling so depressed all week.'

Appeal to pity (Ad misericordiam)

Situation: 'That ridiculous proposal to build a bike lane is so absurd it is only worthy of a hearty laugh.'

Appeal to ridicule

Situation: 'No true scientist would ever question the validity of quantum mechanics.'

No true Scotsman fallacy

Situation: 'You argue that corporate regulations are too strict, but you only say that because you own stock in a major corporation.'

Circumstantial ad hominem (Appeal to motive)

Situation: 'If he studies hard, he will pass the exam. He passed the exam, so he must have studied hard.'

Affirming the consequent

Situation: 'If the factory pollutes the river, the fish will die. The factory does not pollute the river, so the fish will not die.'

Denying the antecedent

Situation: 'Look at this tiny sample of two people who liked our product; therefore, our customer satisfaction rate is 100%.'

Hasty generalization

Situation: 'My grandfather smoked three packs of cigarettes a day and lived to be ninety-five, so smoking cannot be harmful.'

Anecdotal fallacy

Situation: 'Have you finally stopped cheating on your standardized tests?'

Loaded question

Situation: 'Organic food is safe and healthy, implying that all conventional food is inherently dangerous and toxic.'

Loaded label

Situation: 'The coin has landed on heads five times in a row, so tails is definitely due on the next flip.'

Gambler's fallacy

Situation: 'Economic growth is rising because the invisible hand of the market consciously selects which businesses survive.'

Fallacy of misplaced concreteness

Situation: 'You complain about the messy kitchen counter, but what about the piles of old newspapers in your office?'

Red herring (Tu quoque / Whataboutism)

Situation: 'The CEO must be a genius because the company made a profit this quarter, completely ignoring overall economic trends.'

Regression fallacy

Situation: 'I cannot fathom how complex cellular machinery could evolve by natural processes, so it must have been designed by an intelligence.'

Divine fallacy