This set of 41 words covers the abstract vocabulary used to describe logical structure, the reasoning process, and argument evaluation — terms like 論理構造, 推論過程, and 因果律 that recur throughout N1 reading passages on philosophy, science commentary, and critical essays. N1 texts tend to discuss the validity and basis of an argument rather than concrete events, so this vocabulary is what lets a reader follow the actual logic of a passage rather than just its surface content.

This article is part of our JLPT N1 Complete Vocabulary Guide. Practice all 41 words with the Abstract Concepts — Logic & Reasoning Vocabulary deck in Onigiri Anki.

Properties of Logical Systems (9)

Abstract nouns naming intrinsic properties of arguments and systems — necessity versus contingency, identity, regularity, causality, and consistency — the backbone vocabulary for N1 passages that evaluate whether a claim actually holds together.

logicality論理性ronrisei

彼の説明には十分な論理性がある。 — His explanation is sufficiently logical.

logical structure論理構造ronrikouzou

私たちはその議論の論理構造を注意深く確認した。 — We checked the logical structure of the argument carefully.

identity同一性douitsusei

容疑者の同一性はまだ確認されていない。 — The identity of the suspect has not yet been confirmed.

regularity規則性kisokusei

彼の行動には規則性がある。 — There is a regularity in his behavior.

necessity必然性hitsuzensei

謝罪することには必然性があった。 — There was a necessity to apologize.

contingency偶然性guuzensei

二人の出会いには偶然性があった。 — Their meeting involved an element of chance.

appropriateness (proportionality)相当性soutousei

その答えは状況に対して相当性がある。 — The answer is appropriate to the situation.

law of causality因果律ingaritsu

因果律では、すべての結果に原因がある。 — The law of causality says that every result has a cause.

consistency; coherence首尾shubi

彼は最初から最後まで首尾一貫した説明をしました。 — He gave a coherent explanation from beginning to end.

Reasoning Process & Argument Form (8)

Words describing the act of reasoning itself — the path an argument takes, its mode, and the point where it breaks down (論理飛躍) — essential for N1 passages that trace or critique how a writer arrived at a conclusion.

reasoning path理路riro

彼女の理路は明快で、追いやすかった。 — Her reasoning was clear and easy to follow.

plot; structure of an argument筋立てsujidate

その筋立てでは、だれも納得しなかった。 — No one was convinced by that plot.

reasoning; inference推理suiri

彼の推理は惜しかったが、真実には届かなかった。 — His inference was close, but it missed the truth.

logic; reason条理jouri

彼の主張には条理がある。 — His argument has logic.

rational理性的riseiteki

彼はその問題について理性的な答えを出した。 — He gave a rational answer about the problem.

logical leap論理飛躍ronrihiyaku

その説明には論理飛躍がある。 — There is a logical leap in that explanation.

process of inference推論過程suironkatei

推論過程をはっきり説明してください。 — Please explain the process of inference clearly.

mode of reasoning; argumentation論法ronpou

彼の論法は少しわかりにくい。 — His argumentation is difficult to follow.

Discourse Stance & Argument Structure (6)

Vocabulary for describing the shape of a debate and a speaker's position within it — objection, agreement, standpoint, and the structure of a discussion — common in N1 opinion and critique passages.

objection; dissenting opinion異論iron

会議では異論も出た。 — There were some objections during the meeting.

exposition; commentary講釈koushaku

彼はその計画について長く講釈した。 — He gave a long commentary on the plan.

standpoint視座shiza

その問題は、もっと広い視座から考えるべきだ。 — We need to consider the issue from a broader standpoint.

basis; standpoint立脚点rikkyakuten

計画を別の立脚点から見直す必要がある。 — We need to reconsider the plan from a different standpoint.

agreement同意doui

その意見に同意します。 — I agree with that opinion.

structure of an argument/discussion議論構造gironkouzou

彼の議論構造は分かりにくかった。 — His argument's structure was hard to follow.

Truth, Evidence & Verification (6)

Terms for judging whether a claim withstands scrutiny — confirmation, substantiation, likelihood, and true/false or right/wrong judgments — frequent in N1 passages on scientific or legal reasoning.

pros and cons; acceptance or rejection可否kahi

提案の可否は明日決める。 — We will decide whether to accept or reject the proposal tomorrow.

truth or falsehood真偽shingi

そのうわさの真偽はまだわからない。 — The truth or falsehood of the rumor is still unclear.

appropriateness; rightness or wrongness当否touhi

この計画の当否を検討している。 — I am considering the appropriateness of this plan.

substantiation証拠立てshoukodate

彼女は主張を証拠立てるために資料を提示した。 — She presented materials to substantiate her claim.

confirmation; corroboration確証kakushou

彼が関わったという確証がない。 — There is no corroboration that he was involved.

probability; likelihood確からしさtashikarashisa

電車が遅れる確からしさは高い。 — There is a high likelihood that the train will be late.

Relations, Classification & Scope (12)

Words for how concepts connect to, contain, or must be distinguished from one another — correlation, implication, typology, comprehensiveness — plus 恣意性, the arbitrariness such distinctions are meant to guard against.

implications含意gan'i

この決定の含意は深刻です。 — The implications of this decision are serious.

comprehensive coverage網羅moura

この辞書は最新の用語を網羅している。 — This dictionary covers the latest terms.

correlation相関関係soukankankei

運動と睡眠には強い相関関係がある。 — There is a strong correlation between exercise and sleep.

arbitrariness恣意性shiisei

その決定の恣意性が強く批判された。 — The arbitrariness of the decision caused strong criticism.

typology類型ruikei

この作品は、登場人物をいくつかの類型に分けている。 — This work classifies the characters into several types.

summary概括gaikatsu

概括すると、その計画はまだ不十分だ。 — To summarize, the plan is still insufficient.

explanatory power説明力setsumeiryoku

この図は、十分な説明力を持っている。 — This chart has sufficient explanatory power.

limitation限定gentei

その記事には、応募できる人に限定がある。 — The article has restrictions on who can apply.

relation連関renkan

二つの出来事の連関は、まだはっきりしていない。 — The relation between the two events is still unclear.

comprehensiveness網羅性mourasei

このマニュアルは網羅性を重視している。 — This manual emphasizes comprehensiveness.

discrimination; distinguishing弁別benbetsu

裁判所は二つの事案を弁別しなければならない。 — The court must distinguish between the two cases.

partition; categorization区分けkuwake

資料を話題ごとに区分けしました。 — We sorted the materials into categories by topic.

The 性 nominalization pattern, and three near-synonym traps

Eight words in this set — 論理性, 恣意性, 必然性, 偶然性, 相当性, 網羅性, 同一性, 規則性 — are built by attaching the abstract-noun suffix 性 to a root, turning a quality (logical, arbitrary, necessary) into a citable property of an argument or system; once you recognize this productive pattern, unfamiliar 性-nouns become decodable on sight during the exam. Watch for the antonym pair built the same way: 必然性 (necessity) and 偶然性 (contingency) are opposites, so confusing them inverts a sentence's meaning. Separately, 可否, 当否, and 真偽 all express a binary judgment but attach to different domains — 可否 to proposals, 当否 to conduct or decisions, 真偽 to factual claims — and are easy to swap under time pressure. Finally, 視座 and 立脚点 both translate as 'standpoint,' but 視座 is the vantage point one views a matter from, while 立脚点 is the ground one stands on to argue it.

Frequently Asked Questions

What is the difference between 論理性 and 論理構造?

論理性 (ronrisei) is the abstract quality of being logical — whether an argument holds together at all — while 論理構造 (ronrikouzou) is the concrete skeleton of that argument, how its premises and conclusions are arranged. A critic might praise a text's 論理性 while separately diagramming its 論理構造.

Why do so many words in this list end in 性 or 的?

N1 abstract-topic passages constantly need to name qualities rather than things, and 性 ('nature, quality') and 的 ('characteristic of') are the two main suffixes Japanese uses to turn a concept into a describable property — hence 必然性, 恣意性, 網羅性, and 理性的 here. Learning the suffix pattern itself is often more useful than memorizing each word individually, since it transfers to N1 vocabulary you have not seen before.

Practice All 41 Abstract Concepts — Logic & Reasoning Vocabulary Words

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JLPT N1 Abstract Concepts — Logic & Reasoning Vocabulary (2026)