(law) an explanation of the fundamental reasons (especially an explanation of the working of some device in terms of laws of nature); "the rationale for capital punishment"; "the principles of internal-combustion engines"根本的な理由の説明(特に、自然の法則に照らしたある装置の動作の説明)道理
例:The rationale for capital punishment. 死刑に対する正当性。