そもそも論ろん

noun

going back to the beginning of a discussion; revisiting the fundamental points

Used when someone in a discussion or argument insists on returning to the original premise or basic question, often seen as derailing or overly pedantic. The term can carry a slightly negative nuance of nitpicking or avoiding the current point.

See also: そもそも

• 会かい議ぎで彼かれがそもそも論ろんを始はじめたので、話はなしが進すすまなかった。

  He started going back to the beginning in the meeting, so the discussion didn't move forward.