reason · manage

1. Origins, structure, and basic meaning

• Structure: 理 has 11 strokes and concerns reason or principles and the ordering or management of things.
• Basic usage: 整理 is read せいり, and 理屈 is read りくつ.

2. Common pitfalls and similar expressions

• Organizing and reasoning
  • 資料を整理した means organized the materials.
  • 考えを整理する applies the same action to the order and connections of one's thoughts.
  • 仕組みの理屈 is the logic of how something works.
  • In もっともらしい理屈を並べ始めた, the word takes a negative sense: began offering plausible excuses.