logic

Everyday

1. Logic is careful, clear thinking where each step follows from the one before, so you reach a sensible answer. tree →
2. Logic is also the study of correct reasoning, a part of maths and philosophy. tree →
3. The logic of something is the reason or sense behind it: «I don't see the logic of that plan». tree →
4. (computers) Logic is the set of rules and true/false steps a computer or program follows. tree →

In the lessons

In maths, logic puzzles ask pupils to use clues to work out who has which pet or what number is hidden; good answers explain each step. In coding, «if … then … else» and «and / or / not» are logic. In everyday life and stories, someone with logic is calm and reasons well; something «against all logic» is surprising or silly. Phrases: «logic puzzle», «use your logic», «the logic behind», «there's no logic in it», «flawed logic».

Examples

• Use logic to solve the puzzle: the cat is not in the red house. tree →
• There is no logic in walking home in the rain without your coat. tree →
• In coding, logic decides what the robot does next. tree →
• Sherlock Holmes solved crimes with logic. tree →
• Her logic was good, but one fact was wrong. tree →
• We learned about «and», «or» and «not» in logic. tree →
• I can't follow the logic of this rule. tree →

Note

Uncountable: «good logic», not «a logic» in everyday speech. Adjective: logical; opposite: illogical. A logical argument can still reach a wrong answer if one starting fact is false. In maths problems, logic means showing each step that leads to the answer.

In Jewish tradition

In maths, logic puzzles ask pupils to use clues to work out who has which pet or what number is hidden; good answers explain each step. In coding, «if … then … else» and «and / or / not» are logic. In everyday life and stories, someone with logic is calm and reasons well; something «against all logic» is surprising or silly. Phrases: «logic puzzle», «use your logic», «the logic behind», «there's no logic in it», «flawed logic».

Examples

• The translation adopted here follows a popular logic. (Sefer Yetzirah, Sefaria community translation) tree →
• George Boole inThe Laws of Thought, London 1854, p. 48, also says: "The respective interpretations of the symbols 0 and 1 in the system of Logic are Nothing and Universe." (Mordell, The Origin of Letters and Numerals according to Sefer Yetzirah (1914)) tree →

Note

Uncountable: «good logic», not «a logic» in everyday speech. Adjective: logical; opposite: illogical. A logical argument can still reach a wrong answer if one starting fact is false. In maths problems, logic means showing each step that leads to the answer.