A-Level Thinking Skills - Advanced Reasoning & Fallacies

Front

Amphiboly (Syntactic Ambiguity)

Back

A fallacy where a grammatical structure or sentence phrasing allows for multiple interpretations. Unlike equivocation (which relies on a word having multiple meanings), amphiboly relies on the poor construction of the sentence itself to mislead the audience. > **Example:** 'I saw the man with the telescope.' (Did I use the telescope, or did the man have it?)

Front

Tu Quoque ('You Too')

Back

A type of Ad Hominem fallacy where one attempts to discredit an opponent's argument by asserting the opponent's failure to act consistently with that argument. It is a deflection tactic that does not address the truth or falsity of the original claim. > **Real-world:** A smoker dismissing a doctor's advice to quit because the doctor smokes.

Front

The Base Rate Fallacy

Back

An error in reasoning where specific information (e.g., individuating data) is favored over general statistical information (base rates). It often occurs when evaluating the probability of an event under uncertain conditions. > **Math Example:** Ignoring the fact that a disease affects only 0.1% of the population, while focusing solely on a 90% accurate test result, leading to a vastly overestimated risk.

Front

Is-Ought Gap (Hume's Guillotine)

Back

The principle that one cannot derive prescriptive statements (what ought to be) from descriptive statements (what is) without a bridging premise. A factual claim about the state of the world does not logically necessitate a specific moral action unless one assumes a value system. > [!NOTE] Moving from 'X is natural' to 'X is good' is a fallacy known as the Appeal to Nature.

Front

Red Herring

Back

A diversionary tactic that introduces an irrelevant topic to divert attention from the original issue. Unlike the Straw Man (which distorts the argument), a Red Herring simply abandons the argument to chase a distraction. > **Context:** Often used in political debates to avoid answering difficult questions.