Most informal logic is based on analyzing arguments, written in plain English, for known fallacies. Fallacies can occur in all types of arguments (deductive, inductive, abductive) but in deductive arguments a fallacy is regarded as an invalid argument, equivalent to a math mistake which can be established using the rules of inference and equivalence discussed before \[Deductive & Inductive Arguments and Use Cases\](Deductive & Inductive Arguments and Use Cases):
Most informal logic is based on analyzing arguments, written in plain English, for known fallacies. Fallacies can occur in all types of arguments (deductive, inductive, abductive) but in deductive arguments a fallacy is regarded as an invalid argument, equivalent to a math mistake which can be established using the rules of inference and equivalence discussed before [Deductive & Inductive Arguments and Use Cases](Deductive & Inductive Arguments and Use Cases):
1. All dictators are corrupt.
2. All politicians are corrupt.
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@@ -204,7 +204,9 @@ Fallacies of presumption have premises that themselves contain what they purport
_Sodium and chlorine are both deadly poisons. Salt is made up of sodium and chlorine. Therefore salt is a deadly poison._
26.**Division** -- the opposite of composition, where a statement about the whole is taken to be the same for the parts.
_The Nixon administration was composed of a bunch of crooks. Therefore Henry, Nixon's White House chef, was a crook._
_The Federation of American Scientists is prestigious and wise. Therefore John, who is a member, is prestigious and wise._
