想努力溫習卻跟同學去看電影；明知體重超標卻把美味甜品多吃兩碗；明天一早要上學上班卻追看劇集到凌晨三時。
這些心魔戰勝理智的情況天天都發生。當時享受但事後後悔，告訴自己決心下次要有節制但到了下次又一樣重蹈覆轍，怎會這樣？
道德判斷削意志
核心的問題是self-control(自制的能力)。而self-control講的是willpower(意志力)。而willpower要對付的敵人就是temptation(引誘、誘惑)。Kelly McGonigal在The Willpower Instinct中說：
When we think of something that requires willpower, what's the first thing that comes to mind? For most of us, the classic test(經典的、典型的) of willpower is resisting temptation.... When people say, "I have no willpower," what they usually mean is, "I have trouble saying no when my mouth, stomach, heart, or (fill in the anatomical part) wants to say yes."
Anatomical是形容詞，即解剖學上的、結構上的；名詞是anatomy，這個字也可用來指身體的部分、器官。上面一段中的"anatomical part"便作這個解釋。腦筋清醒，但肉體卻抵受不住誘惑。這就是典型的willpower不足。
很多眼前事做不到，長遠目標不能達到，都是受willpower不足拖累。好消息是，willpower是有方法增強的，但很多人卻用錯方法，適得其反。
其中一種問題是把意志力看成是道德上的優點︰
In the quest for self-control, it is a mistake to frame every willpower challenge in moral terms. We are too quick to give ourselves moral credit for good deeds done or merely contemplated, and too good at justifying giving in.
Frame in moral terms就是用道德的框架、角度去看一件事。Contemplate解思考、盤算、預期，例如︰Are you contemplating revenge?(你在盤算報復嗎？)Contemplate也解凝視、注視，例如︰She is contemplating the famous painting.(她凝視那幅名畫。)
把willpower的挑戰看成是道德的對錯，通常會得不償失。這種陷阱可稱為the halo effect(光環效應)：
This form of moral licensing(道德上的准予) looks for any reason to say "yes" to temptation. When we want permission to indulge(滿足欲望), we'll take any hint of virtue as a justification to give in.
面對誘惑，人通常會千方百計去找借口縱容自己。而一丁點“好事”，往往就成為了這個讓自己在另一件事上放縱的借口。
舉個實例，有研究發現，出外用餐，當你點了餐牌上形容為“健康”的主菜，通常你會在飲品、甜品或副菜上吃得超標︰
Although their goal is to be healthy, they end up consuming more calories than people who order a regular entree(主菜).
專注目標與效果
在抵受誘惑的事情上，別老想對與錯。因為這樣反而削弱意志力︰
When we turn willpower challenge into measures of moral worth, being good gives us permission to be bad. For better self-control, forget virtue, and focus on goals and values.
專注於目標與效果，willpower就會強一點。
文︰子慧
