Suppose Smith hates me and does evil to me. The GR would seem still to prescribe returning good for evil.
But that will only encourage Smith! If good consequences follow from Smith’s mistreating me (from myself no less), then why should he stop?
So, the first step might be to present the GR to Smith, asking him whether he’d like to be treated the same way he is treating me.
If that fails, then I’d have to fight him, and the GR is in this situation a vicious principle.
1. I want to be treated X-ly; hence, I’ll treat others X-ly. But there is also:
2. I want to treat others Y-ly; hence, I will agree not to become upset when others treat me Y-ly. But then it follows that: I do not mind being treated Y-ly; hence, I am permitted to treat others Y-ly.
Thus, let’s say I live my life according to the principle “I give no quarter and ask for none myself.” How does the GR evaluate this?
It may be true that I do not mind being treated with no mercy, but it would surely be wonderful if others did show mercy to me. I’d like to be treated with mercy. Hence, I ought to show mercy to others.
It seems that the GR contradicts my more self-interested though still consistent and non-hypocritical ethic. It may be that consistency is bought at too high a price.