きじょうのくうろん
expression, noun
armchair theory; impractical plan; pipe dream
idiomcognition
1. armchair theory; impractical plan
An argument or plan that sounds coherent on paper but cannot work in practice because it ignores real conditions. Almost always used dismissively, of someone else's proposal.
それ机上(きじょう)空論(くうろん)だ。
That is just armchair theory.
現場(げんば)()らない(ひと)机上(きじょう)空論(くうろん)()ぎない
It is nothing more than armchair theorizing by someone who does not know the front line.
予算(よさん)人手(ひとで)(かんが)えていない計画(けいかく)机上(きじょう)空論(くうろん)()わるだろう。
A plan that considers neither budget nor staffing will end up as an impractical theory.

Literally "empty argument on the desk" — 机上(きじょう) (on the desk) + 空論(くうろん) (empty theory). The image is of a plan drawn up at a desk by someone who has never been to the site.

Common collocations

  • 机上(きじょう)空論(くうろん)だ: that is armchair theory
  • 机上(きじょう)空論(くうろん)()ぎない: to be nothing but armchair theory
  • 机上(きじょう)空論(くうろん)()わる: to end up as an impractical idea

Usage

This is a blunt criticism. Directed at a superior or a client it will sound rude, so softer phrasings such as 現実的(げんじつてき)ない (not realistic) are usually chosen in polite settings.