Modus Ponens (MP)
If A the B
A
Therefore B
Hypothetical Syllogism (HS)
If A then B
If B then C
Therefore, if A then C
Modus Tollens (MT)
If A then B
Not B
Therefore, not A
Disjunctive Syllogism (DS) / Modus Tollendo Ponens (MTP)
Either A or B
Not A
Therefore, B
The Fallacy of Affirming the Consequent
Invalid of Modus Ponens (MP)
If A then B
B
Therefore A
The Fallacy of Denying the Antecedent
Invalid Modus Tollens (MT)
If A then B
Not A
Therefore, not B
Invalid Disjunctive Syllogism/Modus Tollendo Ponens
Either A or B
A
Therefore, not B
Invalid Hypothetical Syllogism (HS)
If A then B
If C then B
If A then C
Division
The Fallacy of Division consists of arguing that what is true about a whole (or a collection) is necessarily true about each part of that whole (or each element or subgroup of that collection)
Composition
The Fallacy of Composition consists in arguing that what is true about each part of a given whole (or each element or subgroup of that collection) is necessarily true about the whole (or that collection)
Enthymeme
An abbreviated argument or argument form in which at least one premise is suppressed. Revealing the suppressed premise will make the argument valid in form.
Ex: All Humans are mortal
Therefore, Socrates is mortal.
All Humans are mortal
Socrates is human
T
Accident
The fallacy of accident consists of applying a general rule to a specific case whose unique circumstances make the application of the rule inappropriate. We should never apply rules in a mechanical fashion, because rules are presumptive generalizations wh
Converse accident / Hasty Generalization
The fallacy of converse accident consists in deriving a general rule from specific cases whose unique circumstances make the derivation inappropriate. We should never generalize from unusual, atypical, or unrepresentative cases, because rules are presumpt