The Right Thing For The Wrong Reason

If you donate money to an orphanage, that's a good thing because it helps needy children. If you do it to avoid paying taxes, that's a bad thing because you're being greedy. But in the end, you did still help needy children. So is this a good thing or a bad thing?

The ambiguity is difficult. You did the right thing, but you did it for the wrong reason. Would it have been better to do nothing? It's hard to tell. It may change on a case by case basis. 

More often than not, if somebody did the right thing, that matters more than the reason why. What do you think?