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B1 noun #7,000 most common 10 min read

論拠

ronkyo Top 7,000

Practice it Examples Notes & Tips 論拠 in 30 Seconds

Explanation 論拠 in your Level:

At the A1 level, you don't need to use the word '論拠' (ronkyo). It is a very advanced word. Instead, you should focus on the word '理由' (riyuu), which means 'reason.' For example, if you want to say 'The reason is...', you say '理由は...です' (Riyuu wa... desu). 'Ronkyo' is too formal for basic Japanese. Imagine you are a child; children use 'reason' but not 'logical grounds.' You might hear it on the news, but you can ignore it for now and focus on 'why' (nande/doushite) and 'reason' (riyuu). This word contains difficult kanji that you will learn much later in your studies. Just remember that there are many ways to say 'reason' in Japanese, and this is the most difficult one used by professors and lawyers.

At the A2 level, you might start seeing '論拠' in formal reading passages or news clips, but you still won't use it in daily conversation. You should understand that it is a 'level up' from '理由' (riyuu). While 'riyuu' is used for anything (like why you are hungry), 'ronkyo' is used for arguments. If you are learning about how to express opinions, you might use '根拠' (konkyo) first. 'Konkyo' is easier to use than 'ronkyo.' Think of 'ronkyo' as a special word for school or professional debates. You don't need to memorize it yet, but recognizing the first kanji '論' (ron), which appears in 'ronbun' (essay/thesis), will help you understand that this word is related to writing and formal thinking.

At the B1 level, you are entering the 'Intermediate' stage where you need to distinguish between different types of 'reasons.' '論拠' (ronkyo) is an important word for you to recognize. You should use it when you are writing a formal essay or giving a presentation in Japanese. It means 'logical grounds.' If you say '私の主張の論拠は〜' (The logical grounds for my claim are...), you sound much more professional than if you just use '理由' (riyuu). At this level, you should start noticing how it is used with verbs like '示す' (shimesu - to show) or '挙げる' (ageru - to cite). It is a key vocabulary item for the JLPT N2 exam. You should also start comparing it with '根拠' (konkyo), noting that 'ronkyo' is more about the logic of an argument.

At the B2 level, you should be able to use '論拠' (ronkyo) accurately in both writing and formal speaking. You understand that it is the 'warrant' or 'logical bridge' in an argument. When you participate in a discussion about social issues or business strategies, you should use 'ronkyo' to describe the basis of your reasoning. You should also be familiar with common collocations like '論拠が薄弱だ' (the logical grounds are weak) or '論拠を補強する' (to reinforce the logical grounds). You can distinguish between 'shoko' (physical evidence) and 'ronkyo' (logical reasoning). This word is essential for reading newspaper editorials or academic articles, where authors frequently critique the 'ronkyo' of opposing views.

At the C1 level, you have a nuanced understanding of '論拠' (ronkyo) and can use it to engage in high-level intellectual discourse. You are aware of its legal and philosophical origins. You can use it to dissect complex arguments, pointing out precisely where a 'ronkyo' might be flawed or contradictory. You use phrases like '論拠のすり替え' (shifting the logical grounds) to identify logical fallacies in a debate. Your use of the word is natural and appropriately placed in formal registers. You can also appreciate the stylistic difference between using 'ronkyo' and more classical terms or specific legal jargon. In a professional environment, you use this word to build persuasive, logically sound cases that command respect from native speakers.

At the C2 level, '論拠' (ronkyo) is a tool you use with precision and elegance. You understand its deepest nuances, including how it functions in different academic disciplines (e.g., how a 'ronkyo' in a scientific paper differs from one in a legal brief). You can use the word to write professional-grade critiques, legal documents, or academic papers. You are also sensitive to the 'overuse' of such formal language and know exactly when to switch to more accessible terms depending on your audience. You can explain the historical development of the term and its relation to Buddhist logic (Inmyo) or Western rhetorical traditions. Your mastery of 'ronkyo' reflects a near-native ability to navigate the most sophisticated levels of Japanese communication.

Practice it Examples Notes & Tips

論拠 in 30 Seconds

Ronkyo means 'logical grounds' or 'basis for an argument.' It is a formal term used in academic and professional settings.
Unlike 'konkyo' (general grounds), ronkyo specifically emphasizes the logical connection between evidence and a conclusion.
Commonly used with verbs like 'shimesu' (show), 'ageru' (cite), and 'hokyou suru' (reinforce) in debates and essays.
It is a key vocabulary item for advanced Japanese learners (JLPT N2/N1) and essential for understanding formal media.

The Japanese word 論拠 (ronkyo) is a sophisticated noun primarily used in formal, academic, and professional contexts. At its core, it refers to the logical foundation or the underlying reasoning that supports an argument, a claim, or a specific belief. While many learners might initially confuse it with general words for 'reason' or 'evidence,' ronkyo specifically denotes the logical bridge between a set of facts and the conclusion derived from them. In the realm of critical thinking and debate, if you provide a fact (data) to support a claim, the ronkyo is the principle or warrant that explains why that specific fact is relevant to your conclusion.

Etymological Breakdown: The first kanji, 論 (ron), means theory, logic, or argument. The second kanji, 拠 (kyo), means a foothold, base, or reliance. Together, they literally translate to 'the base of the argument.'

You will most frequently encounter this word in university lectures, legal proceedings, scientific papers, and high-level business strategy meetings. It is not a word you would typically use when explaining to a friend why you chose a specific restaurant for lunch; doing so would sound overly clinical or pedantic. However, if you are writing a thesis or participating in a structured debate about public policy, ronkyo becomes an indispensable tool for articulating the strength of your position.

その主張を裏付けるための明確な論拠を示してください。
(Please provide clear logical grounds to support that claim.)

Understanding the nuance of ronkyo requires distinguishing it from 根拠 (konkyo). While both are translated as 'grounds' or 'basis,' konkyo is broader and can refer to physical evidence or just a general reason for doing something. Ronkyo, conversely, is strictly tied to the process of reasoning. It answers the question: 'By what logic does this evidence prove your point?'

Domain Usage: In Japanese law, ronkyo refers to the specific legal principles or precedents that justify a judicial decision. In philosophy, it represents the premises of a syllogism.

彼の反論は、科学的な論拠に基づいている。
(His counter-argument is based on scientific logical grounds.)

In contemporary Japanese discourse, particularly on social media or news commentary, you might hear the phrase '論拠が薄弱だ' (ronkyo ga hakujaku da), meaning the logical grounds are weak or flimsy. This is a common way to criticize an opponent's argument without necessarily calling them a liar, but rather pointing out that their logic doesn't hold up to scrutiny.

統計データはあっても、それを結論に結びつける論拠が不十分だ。
(Even if there is statistical data, the logical grounds linking it to the conclusion are insufficient.)

Collocational Strength: Commonly paired with verbs like 示す (shimesu - to show), 挙げる (ageru - to cite/list), 欠く (kaku - to lack), and 補強する (hokyou suru - to reinforce).

この論文では、新しい理論の論拠として過去の実験結果を挙げている。
(This paper cites past experimental results as the logical grounds for the new theory.)

裁判官は、被告の主張に十分な論拠がないと判断した。
(The judge determined that there were no sufficient logical grounds for the defendant's claim.)

Mastering 論拠 (ronkyo) involves understanding its grammatical placement and the specific verbs it typically attracts. As a noun, it often functions as the object of a sentence or the subject of a descriptive clause. Because it deals with logic and reasoning, the sentences it appears in are usually complex and formal. Below are several patterns and examples to help you integrate this word into your advanced Japanese repertoire.

Pattern 1: [Noun] を論拠とする (To use [Noun] as logical grounds): This pattern is extremely common in academic writing to state what your argument is based on.

彼は、憲法第９条を論拠として、その政策の違憲性を訴えた。
(Using Article 9 of the Constitution as logical grounds, he appealed the unconstitutionality of that policy.)

Notice how ronkyo acts as the bridge between the law (the source) and the claim of unconstitutionality. Without the word ronkyo, the sentence might just say 'He used Article 9,' but ronkyo specifies that the article provides the logical justification.

Pattern 2: 論拠を挙げる (To cite/adduce logical grounds): Used when someone is asked to prove their point by listing the logic behind it.

反対意見を述べるなら、納得できる論拠をいくつか挙げてください。
(If you are going to state an opposing opinion, please cite several convincing logical grounds.)

Another frequent usage is describing the quality of an argument. Adjectives like 明確な (meikaku na - clear), 確かな (tashika na - certain/solid), or 希薄な (kihaku na - thin/weak) often modify ronkyo.

Pattern 3: 論拠に欠ける (To lack logical grounds): A formal way to say an argument is baseless or poorly supported.

その説は非常に興味深いが、客観的な論拠に欠けている。
(That theory is very interesting, but it lacks objective logical grounds.)

In business contexts, you might hear ronkyo when discussing ROI (Return on Investment) or market entry strategies. Executives want to see the 'ronkyo' before approving a multi-million yen budget.

新規事業の成功を確信するための論拠を、データに基づいて説明した。
(I explained the logical grounds for being confident in the success of the new business based on data.)

学術的な議論においては、常に厳密な論拠が求められる。
(In academic discussions, strict logical grounds are always required.)

While 論拠 (ronkyo) is not a word you'll hear in a casual izakaya conversation or a daily greeting, it is a staple of 'intellectual' Japanese. If you consume Japanese media focused on politics, law, or science, you will hear it constantly. Understanding its natural habitats will help you recognize the register of the conversation immediately.

1. News and Political Debates: On news programs like NHK's 'News 7' or Sunday morning talk shows where pundits discuss government policy, ronkyo is the standard term used to challenge a politician's reasoning. You might hear an interviewer ask: 'その政策の論拠は何ですか？' (What are the logical grounds for that policy?).

政府は増税の論拠として、社会保障費の増大を挙げた。
(The government cited the increase in social security costs as the logical grounds for the tax hike.)

In these contexts, the word emphasizes that the government is expected to provide a rational explanation, not just a whim. It holds the speaker to a standard of accountability.

2. The Legal System: In a courtroom setting or in legal documents (判決文 - hanketsubun), ronkyo is used to refer to the legal reasoning that justifies a verdict. Lawyers will argue that the opposing side's ronkyo is flawed (論拠が破綻している - ronkyo ga hatan shite iru).

弁護人は、検察側の論拠の矛盾を鋭く突いた。
(The defense attorney sharply pointed out the contradictions in the prosecution's logical grounds.)

3. Academic and Scientific Settings: When researchers present findings, they must provide the ronkyo for their hypotheses. In peer reviews, a common critique is that the ronkyo for a specific conclusion is 'weak' (薄弱 - hakujaku) or 'insufficient' (不十分 - fujuubun).

この論文の最大の弱点は、結論に至る論拠が不明確な点にある。
(The biggest weakness of this paper lies in the fact that the logical grounds leading to the conclusion are unclear.)

Finally, you will hear this in corporate 'Logical Thinking' (ロジカルシンキング) workshops. Japanese business culture places a high value on structured reasoning, and ronkyo is a key term in the 'Pyramid Structure' method of communication.

上司を説得するには、感情論ではなく、具体的な論拠が必要です。
(To persuade your boss, you need concrete logical grounds, not emotional arguments.)

彼は自説の論拠を補強するために、最新の統計を引用した。
(He cited the latest statistics to reinforce the logical grounds of his own theory.)

Using 論拠 (ronkyo) incorrectly can make you sound like you're trying too hard to be formal or, conversely, like you don't understand the nuances of logical reasoning. Here are the most common pitfalls English speakers encounter when learning this term.

Mistake 1: Confusing 'Ronkyo' with 'Konkyo' (根拠): This is the most frequent error. While both mean 'grounds,' 根拠 (konkyo) is much more common and versatile. You can have a 'konkyo' for a feeling (e.g., 'I have no grounds for feeling uneasy'), but you cannot have a 'ronkyo' for a feeling. Ronkyo must be tied to an argument or a formal theory. If you use ronkyo for a casual hunch, it sounds bizarre.

❌ 嫌な予感がするが、その論拠はない。
✅ 嫌な予感がするが、その根拠はない。
(I have a bad feeling, but there are no grounds for it.)

Use ronkyo only when there is a 'ron' (论 - argument/theory) involved.

Mistake 2: Confusing 'Ronkyo' with 'Shoko' (証拠): 証拠 (shoko) means 'evidence' in the sense of physical objects, fingerprints, or documents. Ronkyo is the reasoning that makes that evidence matter. If you find a bloody knife, the knife is the shoko. The logical explanation of how that knife proves the suspect's guilt is the ronkyo. Don't call a physical object a 'ronkyo'.

❌ 犯行現場に残された指紋が最大の論拠だ。
✅ 犯行現場に残された指紋が最大の証拠だ。
(The fingerprints left at the crime scene are the biggest evidence.)

Another mistake is using ronkyo in overly casual settings. If your mother asks why you didn't do your chores, and you reply, 'My logical grounds are...', she will likely think you're being sarcastic or disrespectful.

Mistake 3: Misusing the verb 'Reason': English speakers often want to say 'to reason' using ronkyo. However, ronkyo is a noun. To express the act of reasoning, you should use verbs like 推論する (suiron suru) or 論理的に考える (ronriteki ni kangaeru).

❌ 彼は論拠した。
✅ 彼は明確な論拠を提示した。
(He presented clear logical grounds.)

議論の論拠がすり替わっている。
(The logical grounds of the argument have been shifted/replaced.)

Japanese has several words that translate to 'reason' or 'basis.' Choosing the right one is essential for sounding natural and precise. Here is a breakdown of how 論拠 (ronkyo) compares to its closest relatives.

1. 根拠 (Konkyo): Definition: Grounds, basis, foundation.
Comparison: This is the most versatile word. It can be used for logical grounds, physical evidence, or even emotional justification. If you are unsure which word to use, konkyo is almost always a safe bet. Ronkyo is a subset of konkyo that specifically emphasizes the 'logic' part.

根拠のない噂を信じてはいけない。
(Don't believe groundless rumors. - You wouldn't use 'ronkyo' here because rumors aren't formal arguments.)

2. 理由 (Riyuu): Definition: Reason, cause.
Comparison: Riyuu is the most basic and common word. It answers 'why?' in any context. 'Why were you late?' 'Why do you like cats?' Ronkyo is much more formal and refers to the structural logic of a claim, not just a simple cause-and-effect reason.

遅刻した理由を説明してください。
(Please explain the reason for being late. - 'Ronkyo' would sound like you're asking for a philosophical treatise on lateness.)

3. 証拠 (Shoko): Definition: Evidence, proof.
Comparison: Shoko refers to tangible things or verifiable facts that prove something happened. A receipt is shoko that you bought an item. The ronkyo would be the logic that because you have the receipt, you must be the owner.

決定的な証拠が見つかった。
(Decisive evidence was found.)

4. 理屈 (Rikutsu): Definition: Logic, theory, pretext.
Comparison: Often used with a slightly negative connotation to mean 'nitpicking logic' or 'excuses.' While ronkyo is a neutral/positive academic term, rikutsu can imply that someone is being overly argumentative or using logic to avoid the truth.

彼は理屈ばかり言って、行動しない。
(He just spouts logic/excuses and doesn't take action.)

その主張には、歴史的な論拠がある。
(That claim has historical logical grounds.)

How Formal Is It?

Fun Fact

The kanji '拠' (kyo) is also used in the word 'base' (拠点 - kyoten) for military or business operations. Using 'ronkyo' is like saying your argument has a 'strategic base camp.'

Pronunciation Guide

UK rɒn.kjoʊ

US roʊn.kjoʊ

Japanese is a pitch-accent language. In 'ronkyo', the pitch is typically 'Low-High-High' (Heiban style).

Rhymes With

根拠 (konkyo) 布教 (fukyou) 宗教 (shuukyou) - though the vowel is longer 東京 (toukyou) - though the vowel is longer 説教 (sekkyou) 特許 (tokkyo) - similar ending 撤去 (tekkyo) 住居 (juukyo)

Common Errors

Pronouncing it as 'ron-ki-yo' (three syllables) instead of 'ron-kyo' (two syllables).
Confusing the pitch with 'ron-kyou' (long 'o'), which is not a common word.
Stress on the first syllable like English 'ROCK-yo'. Japanese syllables should have equal length.
Mispronouncing the 'r' as an English 'r' instead of the Japanese flap (similar to a 'd' or 'l').
Nasalizing the 'n' too much; it should be a clean uvular nasal sound.

Difficulty Rating

Reading 4/5

The kanji are N2/N1 level, and the word appears in complex sentence structures.

Writing 4/5

Requires understanding of formal grammar and the ability to distinguish it from 'konkyo'.

Speaking 5/5

Hard to use naturally without sounding overly formal or stiff in casual settings.

Listening 3/5

Easily recognized in news or lectures once the sound is memorized.

What to Learn Next

Prerequisites

理由 (riyuu) 根拠 (konkyo) 主張 (shuchou) 議論 (giron) 示す (shimesu)

Learn Next

妥当性 (datousei) 整合性 (seigousei) 反証 (hanshou) 立証 (risshou) 論理 (ronri)

Advanced

帰納法 (kinouhou - induction) 演繹法 (en-ekihou - deduction) 三段論法 (sandan rompou - syllogism) 論理的帰結 (ronriteki kiketsu - logical consequence)

Grammar to Know

〜を〜とする (Regarding A as B)

過去の事例を論拠とする。(To use past cases as logical grounds.)

〜に基づく (Based on ~)

科学的な論拠に基づく判断。(A judgment based on scientific logical grounds.)

〜に欠ける (To lack ~)

客観的な論拠に欠ける主張。(A claim lacking objective logical grounds.)

〜をめぐって (Concerning/Over ~)

論拠の正当性をめぐる論争。(A dispute over the legitimacy of the logical grounds.)

〜を挙げる (To cite/list ~)

三つの論拠を挙げる。(To cite three logical grounds.)

Examples by Level

その理由は分かりません。

I don't know the reason.

A1 students use 'riyuu' (reason) instead of 'ronkyo'.

なぜですか？理由を教えてください。

Why? Please tell me the reason.

Asking for 'riyuu' is the basic way to ask 'why'.

学校に行く理由があります。

I have a reason to go to school.

Simple use of 'riyuu' as a noun.

これが私の理由です。

This is my reason.

Using 'riyuu' to explain a personal choice.

理由は三つあります。

There are three reasons.

Basic counting of reasons.

好きな理由は秘密です。

The reason I like it is a secret.

Common usage in daily life.

理由は特にありません。

There is no particular reason.

Fixed phrase 'tokuni arimasen'.

本当の理由は何ですか？

What is the real reason?

Using 'riyuu' to dig deeper.

その話には根拠がありません。

There are no grounds for that story.

A2 introduces 'konkyo' (grounds) which is simpler than 'ronkyo'.

彼は根拠を示しました。

He showed the grounds/evidence.

Using 'konkyo' to support a simple claim.

反対する根拠を教えてください。

Please tell me the grounds for opposing.

Formal request using 'konkyo'.

科学的な根拠が必要です。

Scientific grounds are necessary.

Adjective 'kagakuteki na' modifying 'konkyo'.

あなたの意見の根拠は何ですか？

What are the grounds for your opinion?

Standard way to ask for justification.

確かな根拠があります。

There are solid grounds.

Using 'tashika na' to describe 'konkyo'.

根拠のないニュースは信じません。

I don't believe groundless news.

Negative modifier 'konkyo no nai'.

理由と根拠は違います。

Reasons and grounds are different.

Starting to differentiate vocabulary.

その主張の論拠を教えてください。

Please tell me the logical grounds for that claim.

B1 students start using 'ronkyo' in formal debates.

彼は明確な論拠を示した。

He showed clear logical grounds.

Common verb 'shimesu' with 'ronkyo'.

論拠が不十分だと指摘された。

It was pointed out that the logical grounds were insufficient.

Passive voice 'shiteki sareta'.

この論文は論拠がしっかりしている。

The logical grounds of this paper are solid.

Describing the quality of writing.

統計データを論拠として使う。

Use statistical data as logical grounds.

Pattern 'A o B to shite tsukau'.

論拠のない批判は無視すべきだ。

Criticism without logical grounds should be ignored.

Using 'ronkyo' to evaluate criticism.

論拠を一つずつ確認しましょう。

Let's check the logical grounds one by one.

Systematic checking of logic.

その説の論拠はどこにありますか？

Where are the logical grounds for that theory?

Asking for the location of logic.

政府はその政策の論拠を説明した。

The government explained the logical grounds for that policy.

Formal institutional usage.

彼の反論は論拠が薄弱だ。

His counter-argument's logical grounds are thin/weak.

Using the specific adjective 'hakujaku'.

論拠を補強するために調査を行う。

Conduct a survey to reinforce the logical grounds.

Verb 'hokyou suru' (to reinforce).

裁判官は論拠の妥当性を認めた。

The judge recognized the validity of the logical grounds.

Legal context with 'datousei' (validity).

論拠をすり替えるのは卑怯だ。

Shifting the logical grounds is cowardly/unfair.

Idiomatic use of 'surikaeru'.

客観的な論拠に基づいて判断する。

Judge based on objective logical grounds.

Pattern 'ni motozuite' (based on).

論拠を挙げる際は、具体性が求められる。

When citing logical grounds, specificity is required.

Nominalized clause with 'motomerareru'.

この議論には共通の論拠が必要だ。

This discussion needs common logical grounds.

Concept of shared premises.

論拠の提示なしに断定するのは危険だ。

It is dangerous to make assertions without presenting logical grounds.

High-level nominalization 'teiji nashi ni'.

その論文は、論拠の構築が極めて緻密だ。

The construction of logical grounds in that paper is extremely meticulous.

Adjective 'chimitsu' (meticulous).

反対派の論拠を論破するのは容易ではない。

Refuting the logical grounds of the opposition is not easy.

Verb 'rompa suru' (to refute/defeat in argument).

歴史的背景を論拠に据える。

Establish historical background as the logical grounds.

Pattern 'o B ni sueru' (to set/place as B).

論拠の欠如が、説得力を削いでいる。

The lack of logical grounds is undermining the persuasiveness.

Abstract subject 'kenjo' (lack).

自説の論拠を再検討する必要がある。

It is necessary to re-examine the logical grounds of one's own theory.

Self-reflective academic context.

論拠が二転三転し、信頼を失った。

The logical grounds kept changing, and trust was lost.

Idiom 'niten santen' (changing repeatedly).

法的な論拠を固めることが最優先だ。

Solidifying legal logical grounds is the top priority.

Verb 'katameru' (to solidify).

論拠の正当性をめぐって、激しい論争が繰り広げられた。

A fierce debate unfolded over the legitimacy of the logical grounds.

Pattern 'o megutte' (concerning).

彼の言説は、形而上学的な論拠に立脚している。

His discourse is based on metaphysical logical grounds.

Verb 'rikkyaku suru' (to be based on).

論拠の脆弱性を突くことが、議論の要諦である。

Pointing out the vulnerability of the logical grounds is the essence of the argument.

Advanced noun 'youtei' (essence/secret).

既存のパラダイムを覆す論拠が提示された。

Logical grounds that overturn the existing paradigm were presented.

Scientific/Philosophical context.

論拠の信憑性が問われる事態となった。

It became a situation where the credibility of the logical grounds was questioned.

Passive 'towareru' (is questioned).

普遍的な論拠を求める姿勢が、学問の神髄だ。

The attitude of seeking universal logical grounds is the essence of scholarship.

Advanced noun 'shinzui' (essence).

論拠を恣意的に解釈してはならない。

One must not interpret logical grounds arbitrarily.

Adverb 'shiiteki ni' (arbitrarily).

論拠が多層的に構成されており、反論の余地がない。

The logical grounds are structured in multiple layers, leaving no room for refutation.

Adverb 'tasouteki ni' (multi-layered).

Synonyms

根拠証拠理由裏付け典拠

Antonyms

憶測独断

Common Collocations

論拠を示す

論拠を挙げる

論拠が薄弱だ

論拠に欠ける

論拠を補強する

論拠が不明確だ

論拠を求める

論拠に基づく

論拠のすり替え

論拠を固める

Common Phrases

論拠が乏しい

— To have scarce or insufficient logical grounds. Used to criticize a weak argument.

その理論はまだ論拠が乏しい。

論拠を明示する

— To clearly state or demonstrate the logical grounds. Common in academic writing.

出典とともに論拠を明示してください。

論拠に乏しい主張

— A claim that lacks sufficient logical support. Often used in peer reviews.

論拠に乏しい主張は受け入れられない。

論拠を再考する

— To reconsider or rethink the logical basis of an argument.

一度、自分の論拠を再考してみるべきだ。

論拠の妥当性

— The validity or appropriateness of the logical grounds.

論拠の妥当性を厳密にチェックする。

論拠を論破する

— To logically defeat or refute the opponent's grounds.

彼は相手の論拠を鮮やかに論破した。

論拠の構築

— The construction or building of a logical argument's foundation.

論文執筆において論拠の構築は重要だ。

論拠を共有する

— To share or agree upon the logical basis with others.

チーム内で論拠を共有しておく。

論拠の欠如

— The total lack of logical grounds.

論拠の欠如が最大の懸念点だ。

論拠の一貫性

— The consistency of the logical grounds throughout an argument.

論拠の一貫性を保つことが大切だ。

Often Confused With

論拠 vs 根拠 (konkyo)

Konkyo is more general. Ronkyo specifically focuses on the logic of an argument.

論拠 vs 証拠 (shoko)

Shoko is physical evidence. Ronkyo is the reasoning behind the evidence.

論拠 vs 理屈 (rikutsu)

Rikutsu can be negative (nitpicking). Ronkyo is neutral and academic.

Idioms & Expressions

"論拠を失う"

— To lose one's logical standing or the basis for one's argument. Used when a premise is proven wrong.

新事実の発見により、彼の説は論拠を失った。

Formal

"論拠を盾にする"

— To use logical grounds as a shield or defense. Often implies relying heavily on a specific rule or logic.

法律の論拠を盾にして、彼は沈黙を守った。

Formal

"論拠が崩れる"

— For the logical foundation of an argument to collapse or crumble.

前提条件が変われば、論拠も崩れてしまう。

Formal

"論拠を突き詰める"

— To investigate or follow the logic to its ultimate conclusion.

論拠を突き詰めると、一つの真実にたどり着く。

Formal

"論拠を並べ立てる"

— To list many logical grounds in a row, sometimes implying an attempt to overwhelm or confuse.

彼はもっともらしい論拠を並べ立てて、客を説得した。

Neutral

"論拠に詰まる"

— To be at a loss for logical grounds; to be unable to provide a reason.

鋭い質問をされ、彼は論拠に詰まってしまった。

Neutral

"論拠を捻り出す"

— To squeeze out or fabricate logical grounds with effort, often implying the grounds are weak.

苦し紛れに論拠を捻り出したが、誰も信じなかった。

Informal

"論拠の矛先を変える"

— To change the direction or focus of the logical argument.

彼は論拠の矛先を変えて、責任を逃れようとした。

Neutral

"論拠を鵜呑みにする"

— To swallow the logical grounds whole without questioning them.

専門家の論拠を鵜呑みにするのは危険だ。

Neutral

"論拠が揺らぐ"

— For the logical grounds to become shaky or uncertain.

スキャンダルによって、彼の政治的論拠が揺らいでいる。

Formal

Easily Confused

論拠 vs 理由 (riyuu)

Both mean 'reason.'

Riyuu is common and broad; ronkyo is formal and specifically refers to logical grounds in an argument.

遅刻の理由 (Reason for being late) vs. 違憲の論拠 (Logical grounds for unconstitutionality).

論拠 vs 裏付け (urazuke)

Both refer to supporting a claim.

Urazuke is often used for corroborating evidence or 'backing up' a story; ronkyo is the logical basis itself.

アリバイの裏付け (Corroboration of an alibi) vs. 仮説の論拠 (Logical grounds for a hypothesis).

論拠 vs 典拠 (tenkyo)

Both refer to a basis.

Tenkyo specifically refers to the authoritative source or text cited as proof.

故事の典拠 (The source of a classical allusion) vs. 議論の論拠 (The logical grounds of an argument).

論拠 vs 因果 (inga)

Both involve reasoning.

Inga refers to cause and effect; ronkyo refers to the logical justification for a claim.

因果関係 (Cause-and-effect relationship) vs. 主張の論拠 (Logical grounds for a claim).

論拠 vs 論理 (ronri)

Both related to logic.

Ronri is the system of logic itself; ronkyo is the specific ground or basis within that system.

論理が通っている (The logic is sound) vs. 論拠を示す (To show the logical grounds).

Sentence Patterns

[Noun] の論拠は [Noun] です。

その説の論拠は、古い文献です。

[Noun] を論拠として [Verb]。

データを論拠として説明する。

論拠が [Adjective] です。

彼の論拠は不十分です。

[Noun] に基づく論拠を挙げる。

事実に基づく論拠を挙げる。

論拠の [Noun] が問われている。

論拠の妥当性が問われている。

[Verb-Plain] ことが論拠となっている。

人口が減っていることが論拠となっている。

論拠を [Adverb] に解釈する。

論拠を恣意的に解釈する。

論拠の [Noun] を鋭く突く。

論拠の脆弱性を鋭く突く。

Word Family

Nouns

理論 (riron - theory)

議論 (giron - discussion/argument)

根拠 (konkyo - grounds)

拠点 (kyoten - base/hub)

Verbs

論じる (ronjiru - to argue/discuss)

拠る (yoru - to be based on/depend on)

Adjectives

論理的な (ronriteki na - logical)

論争的な (ronsouteki na - controversial)

論説 (ronsetsu - editorial)

立論 (ritsuron - making an argument)

証拠 (shoko - evidence)

推論 (suiron - inference)

弁論 (benron - oratory/debate)

How to Use It

frequency

High in written Japanese and formal media; low in daily conversation.

Common Mistakes

Using 'ronkyo' for simple personal reasons. → Use 'riyuu' (理由).
Saying 'The logical grounds for me liking ice cream are...' sounds very strange and robotic.
Confusing 'ronkyo' with physical evidence. → Use 'shoko' (証拠).
A bloody fingerprint is a 'shoko.' The reasoning that the fingerprint proves guilt is the 'ronkyo.'
Treating 'ronkyo' as a verb. → Use 'ronkyo o shimesu' (論拠を示す).
'Ronkyo' is a noun and cannot be used as a suru-verb like 'ronkyo-suru.'
Using 'ronkyo' when you mean 'pretext' or 'excuse' in a negative way. → Use 'rikutsu' (理屈) or 'koujitsu' (口実).
'Ronkyo' is generally a neutral or positive academic term. Using it for a lie sounds odd.
Using the wrong kanji (e.g., 論去). → Use 論拠.
The second kanji must be 拠 (base/foothold), not something that sounds similar.

Tips

Use in Writing

When writing a formal report, use 'ronkyo' to introduce the logical steps that led to your conclusion. This adds a layer of professionalism that 'riyuu' lacks.

Debate Strategy

If you want to challenge someone politely in a formal setting, ask: 'その論拠を詳しく教えていただけますか？' (Could you tell me more about the logical grounds for that?)

JLPT Tip

In reading sections, look for 'ronkyo' when you need to find the author's reasoning. It often appears right before or after a key supporting fact.

Konkyo vs Ronkyo

If you are talking about a gut feeling or a non-formal reason, use 'konkyo'. If you are talking about a structured argument, use 'ronkyo'.

Avoid Repetition

In a long piece of writing, alternate between '論拠', '根拠', and '立論の基礎' to keep the text engaging.

Legal Context

If you are studying Japanese law, pay close attention to '法的論拠' (legal grounds), as it is the basis for all judicial reasoning.

Kanji Meaning

Remember the kanji: 論 (Argument) + 拠 (Base). It's the 'Argument Base'.

Business Etiquette

Presenting a clear 'ronkyo' for your ideas shows that you respect your colleagues' time and intelligence by providing a rational explanation.

Watching News

Try to spot the word 'ronkyo' during political interviews on NHK. It's a great way to see how the word is used to hold leaders accountable.

Evaluate Arguments

Practice identifying the 'ronkyo' in English articles first, then try to express those same logical links in Japanese using the word.

Memorize It

Mnemonic

Think of 'RON' (like a person named Ron) standing on a 'KYO' (Kyoto) base. Ron is in Kyoto to build a strong logical argument.

Visual Association

Imagine a tall bridge connecting two cliffs. The bridge is the 'Ronkyo,' and the cliffs are 'Evidence' and 'Conclusion.' Without the bridge, you can't get across.

Word Web

論 (Logic) 拠 (Base) 論文 (Essay) 根拠 (Grounds) 議論 (Debate) 拠点 (Hub) 理論 (Theory) 立論 (Assertion)

Challenge

Try to write three sentences about a news topic you read today. Use 'ronkyo' to describe why the reporter's conclusion was or was not believable.

Word Origin

The word is composed of two kanji: '論' (ron) and '拠' (kyo). '論' traces back to the concept of arranging words or speech into a coherent structure (theory/argument). '拠' refers to a place where one stands or something one leans on (foothold/base).

Original meaning: In classical contexts, it referred to the textual or philosophical foundation of a specific school of thought.

Sino-Japanese (Kango).

Cultural Context

Avoid using 'ronkyo' in personal relationships (e.g., with a spouse or child) as it can come across as cold, robotic, or overly confrontational.

In English, we often say 'What's your point?' or 'Why do you say that?'. In Japanese, asking for a 'ronkyo' is the formal equivalent of asking for the 'warrant' in the Toulmin Model of Argumentation.

Legal documents from the Supreme Court of Japan (Saiko Saibansho). Logical Thinking books like 'Logical Presentation' by Teruya and Okada. NHK's 'Debate' series where experts discuss national issues.

Practice in Real Life

Real-World Contexts

Academic Writing

論拠を提示する
論拠に基づく考察
論拠の妥当性を検証する
先行研究を論拠とする

Legal Proceedings

法的な論拠
論拠の矛盾
論拠を盾にする
判決の論拠

Business Strategy

投資の論拠
論拠を補強するデータ
論拠が明確な提案
市場分析を論拠とする

Formal Debate

論拠を挙げる
論拠を論破する
論拠のすり替えを指摘する
共通の論拠に立つ

Journalism/News

政府の論拠
論拠が薄弱な政策
批判の論拠
論拠を求める声

Conversation Starters

"その意見には、どのような論拠があるのでしょうか？ (What kind of logical grounds are there for that opinion?)"

"この結論に至った最大の論拠は何ですか？ (What is the primary logical basis for arriving at this conclusion?)"

"相手の論拠をどうやって論破すべきだと思いますか？ (How do you think we should refute the opponent's logical grounds?)"

"今の議論、少し論拠がずれていませんか？ (Don't you think the logical grounds of the current discussion have shifted a bit?)"

"もっと具体的な論拠を提示していただけますか？ (Could you please present more concrete logical grounds?)"

Journal Prompts

今日読んだニュース記事の論拠は、あなたにとって納得できるものでしたか？その理由を書いてください。 (Was the logical basis of the news article you read today convincing to you? Write the reasons.)

あなたが一番大切にしている信念の論拠は何ですか？論理的に説明してみてください。 (What are the logical grounds for the belief you cherish most? Try to explain it logically.)

仕事や学校で、誰かを説得するために使った論拠について思い出して書いてください。 (Recall and write about the logical grounds you used to persuade someone at work or school.)

「論拠」と「感情」のどちらが人を動かすのに重要だと思いますか？あなたの考えを述べてください。 (Which do you think is more important for moving people: 'logical grounds' or 'emotion'? State your thoughts.)

もし自分が裁判官だったら、どのような論拠を最も重視しますか？ (If you were a judge, what kind of logical grounds would you value most?)

Frequently Asked Questions

10 questions

Rarely. It is almost exclusively used in formal situations like business meetings, academic writing, or news discussions. In daily life, people use 'riyuu' or 'konkyo'.

Not exactly. 'Shoko' is the word for physical evidence. 'Ronkyo' is the logic that explains why that evidence supports your point.

'Konkyo' is a general term for grounds or foundation. 'Ronkyo' is a more specific term that emphasizes the 'logic' (ron) of the argument. You can have a 'konkyo' for a feeling, but not a 'ronkyo'.

Yes, it is typically considered an N2 or N1 level vocabulary word. It appears frequently in the reading comprehension sections of these exams.

No, it is a noun. You must pair it with a verb like 'shimesu' (show) or 'ageru' (cite) to express an action.

It means the logical grounds are weak or thin. It's a common way to criticize someone's argument as being poorly thought out.

It is written as 論拠. The first kanji is 'ron' (argument) and the second is 'kyo' (base).

Yes, it can make you sound very professional and logical if you use it to explain your career choices or skills, but don't overdo it.

Yes, both share the kanji '論' (ron). A 'ronbun' (thesis/essay) is where you would most likely find many 'ronkyo' (logical grounds).

The best equivalents are 'logical grounds,' 'basis,' or 'warrant' (in the context of formal argumentation models).