Partial fulfillment of promises

A classic joke: You arrive in the Soviet Union. At the airport you see two people working. One is digging holes in the ground. The other is filling them in. You ask them what they are doing. They say: “The guy who was supposed to be planting trees didn’t show up.”

So, suppose I promise to dig a hole in your yard and plant a tree there. But I couldn’t obtain the tree. Obviously, I shouldn’t dig the hole. Thus, sometimes, partial fulfillment of a promise is no use at all, or worse.

But it seems that sometimes partial fulfillment is my duty. If I promise to give you two T-shirts and but I only manage to obtain one, it seems I owe you that one. But even that depends on the context. Suppose the two T-shirts were to be for a party where a parent and their child were to wear matching clothes. Then one T-shirt might be useless.

Perhaps the story is this. When I can’t fulfill a promise, I need to make it up to you as best as possible. Partial fulfillment is a way of making it up, and it is a default component of making up. But sometimes it’s worthless, in which case I should ask you if there is some other way you’d like me to make up for it.