I was discussing forgiveness with a Jewish friend who objected to the smug way Christians frequently talk about loving their enemies. "It's all very well for them", he said, "but no one has tried to wipe out their entire race. Am I supposed to love Hitler?" He wasn't advocating unrestrained vengeance but I think he felt that feeling love for someone as monstrous as Hitler was somehow a betrayal of his moral values in general and his own race in particular.
Of course the standard Christian response is to assert that Jesus was not talking about love in the usual sense entailing intense intimacy and warm emotion. His love was a matter of attitude and did not involve "feeling" anything in particular.
But what kind of a love is it that involves no emotional element? Have you ever seen it depicted in a novel? Elsewhere, Jesus talks about the need for his followers to "hate" their father and mother (Luke 14:26). Is this supposed to be a species of "emotionless dislike"? Surely the formula "unemotional love" is just a fudge invented to rationalize what is clearly an absurd imperative. But perhaps that's what it's supposed to be.
I think what Jesus was getting at can be illuminated by considering three features of his teaching that are frequently overlooked.
FIRSTLY, Jesus was not an ethicist let alone a philosopher. He did not promulgate a theory of good action or a systematised code of conduct. He was a rabbi in the Wisdom tradition uttering pithy aphorisms and parables. He had far more in common with Aesop than Aristotle. That's not to say that Jesus did not have general moral principles. He was a first century Jew (not a Christian - note) and derived his ethics from his Judaism. However, when his fellow Jews did not take up Christianity in a big way the apostles, and Paul in particular, altered their marketing strategy and tried selling it to the Gentiles instead - with spectacular success. However, being severed from its Jewish roots, all that was left of Christian ethical teaching was a loose set of out-of-context sayings and stories - hardly enough on which to run a civil state, let alone a private life. Consequently, Christian ethical teaching has, since the earliest days, been a cobbling together of whatever ethical ideas were current in the host society, decorated with the sayings of Jesus to provide them with a specious authority.
The fact is, aphorisms do not embody general principles. They are literary "snapshots" depicting in a vivid manner typical human scenarios and plausible responses. We make a mistake if we treat them as codes of conduct rather than goads to thinking. Take, for example, two very cliched English sayings: "Too many cooks spoil the broth" and "Many hands make light work". If we understand them as general principles they contradict each other. But that's not how they work. They are intended draw our attention to "typical" human situations not "general" ones. "Love your enemies", therefore, should not be read as a universal moral rule. Rather, it is intended to suggest that we adopt the simple attitude of generosity to others - even those with whom we are in conflict. It does not prescribe specific behaviour.
SECONDLY, Jesus, being more of a litterateur than a philosopher, frequently used figures of speech such as deliberate paradox and hyperbole (eg, camels going through eyes of needles and beams of wood in neighbours' eyes). In the case of "loving your enemy" the absurdity and over-statement, and the way that it flies in the face of common sense, is a way of stimulating the listener into reflecting on their relationships with their enemies.
THIRDLY, when Jesus uttered an aphorism it was frequently declared as an antithesis to conventional interpretations of the Jewish tradition. ("In the past you were told... but I tell you..."). In this case Jesus is contrasting loving enemies with the old rule of an eye-for-an-eye. Mind you, the latter was an improvement on previous codes in the Ancient World where it was legitimate to impose greater suffering on the offender than they had caused you in the first place. Here Jesus is saying that we should rachet-up our response to the next level which is to renounce strict calculations of revenge and be open-handed.
So is that it? Is Jesus merely saying "be generous"? Yes - I think that's all it amounts to. Everything else is a reading-back into the words of Jesus our current values and ideals. But "love your enemies" is not a trivial point. It's simply not a complete philosophy of life which, I am afraid, many people look to Jesus for.