noun
idealistic theory; unrealistic argument
Refers to a theory or argument that is based on ideals rather than practical considerations, often implying it is unrealistic or naive.
彼の提案は理想論に過ぎない。
His proposal is nothing more than an idealistic theory.
理想論だけでは現実の問題は解決できない。
You can't solve real-world problems with just idealistic arguments.