自明

• Reading: じめい
• Romaji: jimei
• Kanji breakdown: 自 (ji/shi/mizuka) — self, oneself; 明 (mei/aka) — bright, clear
• Pronunciation: /dʑi.meː/

Meaning

Self-evident; obvious; axiomatic. Something that needs no proof or explanation.

A na-adjective and noun describing something so obvious that it requires no further explanation or proof. Common in academic and logical contexts, especially in the phrase 自明のこと (self-evident matter) or 自明の理 (self-evident truth). In mathematics, 自明 is used as a technical term meaning 'trivial.' More formal and intellectual than 明らか (clear, obvious).

Examples

1. それは自明のことであり説明の必要がない。 That is self-evident and requires no explanation.
2. 健康が大切だということは自明の理だ。 It is a self-evident truth that health is important.
3. 自明な結論に至るまでに長い議論が必要だった。 It took a long debate to arrive at what turned out to be an obvious conclusion.

Usage Guide

Context: academic, logic, argument

Tone: academic

Origin & History

From Chinese 自明. 自 (ji) means 'self' and 明 (mei) means 'bright, clear.' Literally 'self-illuminating' — something that is clear by its own nature without external explanation.

Cultural Context

Era: Pre-modern

Generation: All ages

Social background: Academic/Professional