a fortiori

argument

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July 22, 2026

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The phrase "a fortiori" is Latin for "from the stronger argument". It is used in logic and rhetoric to introduce a conclusion that is even more obvious or convincing than a previous one.12

For example, if it's difficult to teach English grammar to native speakers, it follows with even greater reason that it would be challenging to teach it to non-native speakers. This type of argument infers that a conclusion is more certain because a related, less certain statement is already accepted as true. The term has been in use since at least 1561.12

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rhetoric
Basis of agreement and types of argumentation
…pari (arguing from similar propositions), a fortiori (arguing from an accepted conclusion to an even more evident one), a contrario (arguing from an accepted conclusion to the rejection of its contrary), and the argument of authority. The traditional figures of rhetoric are usually only abridged arguments, as, for instance, a…
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…pari (arguing from similar propositions), a fortiori (arguing from an accepted conclusion to an even more evident one), a contrario (arguing from an accepted conclusion to the rejection of its contrary), and the argument of authority. The traditional figures of rhetoric are usually only abridged arguments, as, for instance, a…
Read More