Translation guide
The quality of being based on reason or logic rather than emotion. In Japanese, this concept is often expressed through nouns like 合理性 (gōrisei) and 理性 (risei), as well as adjectives and phrases describing logical thinking.
Expressing that something is based on reason or logic, or the quality of being rational.
The most direct translation for 'rationality' as a quality or property. Often used in formal or academic contexts.
この計画には合理性が欠けている。
This plan lacks rationality.
Refers to the human faculty of reason, often contrasted with emotion or instinct. Closer to 'reason' as a mental capacity.
理性に従って行動する。
Act according to rationality.
A common phrase meaning 'to be rational' or 'to make sense'. Used in everyday conversation.
彼の意見は理にかなっている。
His opinion is rational.
Na-adjective meaning 'rational' or 'logical'. Often used to describe decisions, methods, or thinking.
合理的な判断を下す。
Make a rational judgment.
Emphasizing the contrast between reason and emotion.
A set phrase meaning 'reason and emotion'. Used when discussing the balance or conflict between the two.
理性と感情のバランスが大切だ。
The balance between rationality and emotion is important.
Means 'calmness' or 'composure', often implying rationality in the face of emotional situations.
彼は冷静さを失わなかった。
He didn't lose his rationality.
Referring to efficiency, cost-effectiveness, or practical reason.
Specifically means 'economic rationality'. Used in business or policy contexts.
その政策は経済合理性に欠ける。
That policy lacks economic rationality.
Means 'efficiency', often overlapping with practical rationality in resource use.
効率性を重視する。
Emphasize rationality (efficiency).
合理性 (gōrisei) refers to the quality of being rational, often in a logical or systematic sense. 理性 (risei) is the faculty of reason itself, the human capacity for rational thought. Use 合理性 when talking about the rationality of a plan or decision, and 理性 when referring to a person's ability to think rationally.
Directly translating 'rationality' as ラショナリティ (rashonariti) is not common and may sound unnatural. Stick to the Japanese terms provided.