Don't you realise that Stevens is the personification of dignity and duty and discretion?

discretion 来自动词 discern（辨别、识别），加上名词后缀 -tion 构成。本义是"辨别力"，引申为"谨慎、审慎"，指在言行中能够恰当判断、避免冒犯或泄露秘密的品质。