理論|りろんriron[1]atamadaka (head-high)

1. nountheory
   その考かんがえが彼かれの理論りろんの基礎きそとなっている。↗

   The idea underlies his theory.

• SynonymセオリーNeutralLoanword for a theory or an established formula, as in 「セオリー通り」; in speech it often means the standard play, while 「理論」 is the academic, systematic term.
• Synonym原理げんりWrittenWritten/formal prose. A fundamental principle, as in 「てこの原理」; leans toward the basic laws of how things work.
• Synonym学説がくせつWrittenWritten/formal prose. A theory put forward by scholars, as in 「新しい学説」; leans toward one school's view.
• Synonym説せつNeutralA theory or account, as in 「別の説」; leans toward a viewpoint, which need not form a system.
• Synonym理屈りくつCasualColloquial. Reasoning or twisted logic, as in 「理屈をこねる」; often carries a negative nuance.
• Related論理ろんりWrittenWritten/formal prose. Logic or a coherent line of thought, as in 「論理的に考える」; focuses on whether reasoning holds together.
• Related枠組みわくぐみNeutralA framework or structure, as in 「制度の枠組み」; points to the overall structure, not the content of a theory.
• Related体系たいけいWrittenWritten/formal prose. Knowledge organized into a system, as in 「法体系」; leans toward structure and organization.
• RelatedロジックNeutralLoanword for logic, as in 「ロジックが破綻する」; leans toward business and IT.
• RelatedフレームワークNeutralLoanword for an analytical or development framework; leans toward business and IT.
• Antonym実践じっせんNeutralPractice, the counterpart of 「理論」, as in 「理論と実践」.
• Antonym実際じっさいNeutralActual conditions or reality; opposes 「理論」 in the sense of theory on paper versus what actually happens.

Use 「理論」 for a systematic theory, as in 「相対性理論」 and 「理論上は可能」. Say 「原理」 for fundamental principles, 「論理」 for logic, and 「学説」 for a school's view. セオリー often means the standard play in speech; ロジック and フレームワーク lean toward business and IT. 枠組み and 体系 are about structure; 説 is a view that need not be systematic; 理屈 is colloquial and often negative. The opposites are 「実践」 and 「実際」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 原理げんりや原則げんそくから、筋道すじみちを立たててまとめられた体系たいけい。