Translation guide
The English word "logic" covers a range of meanings from formal reasoning to common sense. This guide helps you choose the right Japanese expression depending on whether you mean the academic discipline, a way of thinking, or the rationale behind something.
Referring to logic as a field of study, formal logic, or logical systems.
The standard term for the academic study of logic. Used in philosophy, mathematics, and computer science.
彼は大学で論理学を専攻している。
He is majoring in logic at university.
Can mean 'logic' in a broad sense, often used in compounds like 論理的 (logical). Less specific than 論理学 when referring to the discipline.
このプログラムは論理に基づいている。
This program is based on logic.
Describing a particular method of reasoning or a logical thought process.
The most common word for 'logic' as a way of thinking. Used in phrases like 論理的な考え方 (logical way of thinking).
彼の論理は理解できない。
I can't understand his logic.
もっと論理的に考えてください。
Please think more logically.
Often implies theoretical or abstract reasoning, sometimes with a negative nuance of being overly argumentative or hair-splitting.
Refers to reason or the natural order of things. Often used in set phrases like 道理で (no wonder).
Explaining the underlying reason or justification for an action, decision, or phenomenon.
The most straightforward word for 'reason' or 'rationale'. Use this when 'logic' simply means the reason why.
その決定の理由を説明してください。
Please explain the logic behind that decision.
Means 'basis' or 'grounds'. Used when emphasizing the foundation or evidence for a claim.
Means 'reason' or 'coherence' in a more abstract sense. Often used in phrases like 筋が通っている (it makes sense).
彼の話は筋が通っている。
His story has logic to it.
Using 'logic' to mean something that is obviously sensible or reasonable in everyday situations.
Means 'common sense'. Often the best translation when 'logic' refers to what any reasonable person would think.
そんなの常識で考えればわかるでしょ。
You can figure that out with simple logic.
Means 'obvious' or 'natural'. Used when the logic is self-evident.
論理 is neutral and often positive, referring to sound reasoning. 理屈 can imply overly theoretical or argumentative logic, sometimes used dismissively (e.g., 理屈っぽい meaning 'argumentative').
The loanword ロジック exists but is mainly used in technical or business contexts (e.g., ロジックモデル). In everyday speech, it can sound unnatural or like jargon.
その議論には論理がない。
There's no logic in that argument.
あなたの論理についていけません。
I don't follow your logic.
このルールの根拠は何ですか？
What's the logic behind this rule?
I understand the logic, but my emotions can't keep up.
彼の言うことには道理がある。
There is logic in what he says.
There is no logical basis for that claim.
それは当たり前の論理だ。
That's just basic logic.