He wants to bring out the intuition

他想要引出这一直觉
and make plausible the idea

并证明他的观点
that what confers moral worth on an action is that it be done because it's right

行为之所以有道德价值是因为行为本身正确
He says suppose there's a shopkeeper

他假设有个店主
and an inexperienced customer comes in.

然后一位外行顾客进到他到店里
The shopkeeper knows that he could give the customer the wrong change,

店主知道他可以给那名顾客找错零钱
could shortchange the customer and get away with it;

给他少找些钱并且可以逃过处罚
at least that customer wouldn't know.

至少那顾客不会知道
But the shopkeeper nonetheless says,

但是店主依然会琢磨
"Well, if I shortchange this customer,

"如果我给这个顾客少找了钱
word may get out, my reputation would be damaged,

也许会有传言我的名誉会受到损害
and I would lose business,

这样我也就没生意做了