formal logic

IPA/fˈɔːməl lˈɒdʒɪk/
IPA/fˈɔːɹməl lˈɑːdʒɪk/

formal logic — noun

1. the study of arguments that uses rules and symbols to decide if reasoning is val

1.nounC1
Definition

the study of arguments that uses rules and symbols to decide if reasoning is valid based only on the structure of statements, not on what the statements are about

Example

Cole learned the basic rules of formal logic in his first philosophy class.

collocation: rules of formal logic

Formal logic helps people find mistakes in arguments that are not obvious at first.

Common collocations
  • rules of formal logic
  • principles of formal logic
  • system of formal logic
  • formal logic of mathematics
  • formal logic of language
Synonyms
  • symbolic logic

    a branch of formal logic that mainly uses symbols and mathematical methods; more specific than formal logic

  • mathematical logic

    formal logic applied to mathematical reasoning, using mathematical notation; overlaps with formal logic but has a narrower scope

Antonyms
  • informal logic

    the study of everyday reasoning in natural language without symbols or strict formal rules

Grammar Patterns

formal logic + of + [field/domain]

Usage Note

This phrase is uncountable — it is not used with 'a' unless referring to a specific system (e.g., 'Aristotle developed a formal logic'). It often pairs with 'of' to name a particular field: 'the formal logic of mathematics'.

Common Mistakes

I studied a formal logic in university.
I studied formal logic in university.
The phrase is uncountable and does not need an article when referring to the field in general.

Etymology

GreekLatinFrenchEnglish

The word 'formal' comes from Latin 'formalis', meaning 'relating to form or shape'. 'Logic' traces back through Latin 'logica' to Greek 'logikē' (the art of reasoning), which comes from 'logos' (word, reason, thought). The phrase 'formal logic' emerged in English in the 19th century to describe the approach to logic that focuses on the form — rather than the content — of arguments.