理屈

1. Origins, structure, and basic meaning

• Structure: 理屈, read りくつ, means a principle or reasoned explanation and can also mean an excuse in context.
• Basic usage: It is used for understanding how a mechanism works or for a latecomer offering plausible explanations.
  • 仕組みの理屈が分かれば、故障の原因も見つけやすい。

2. Common pitfalls and similar expressions

• Neutral reasoning and unwelcome explanations
  • 理屈 does not always mean an excuse or a lie. An expression such as 理屈を並べる, describing a string of explanations, can convey disapproval.