The Buddhists believe that we should never be angry at others who do us harm because firstly, they will reap the negative karma of their actions in due course, and secondly they give us the opportunity to practice compassion and patience. If there are no obstacles in the world how can we practice? So from a negative, a positive is produced.
I found this concept echoed in a passage from ‘The Golden Sayings of Epictetus’ translated by George Long. I should not be surprised that this concept had a name thousands of years ago: Epictetus calls it the rod of Hermes.
Can any profit be derived from these men?
Aye, from all.
What, even from a reviler?
Why, tell me what profit a wrestler gains from him who exercises him beforehand? The very greatest: he trains me in the practice of endurance, of controlling my temper, of gentle ways. You deny it. What, the man who lays hold of my neck, and disciplines loins and shoulders, does me good, … while he that trains me to keep my temper does me none? This is what it means, not knowing how to gain advantage from men! Is my neighbour bad? Bad to himself, but good to me: he brings my good temper, my gentleness into play. Is my father bad? Bad to himself, but good to me. This is the rod of Hermes; touch what you will with it, they say, and it becomes gold. Nay, but bring what you will and I will transmute it into Good. Bring sickness, bring death, bring poverty and reproach, bring trial for life – all these things through the rod of Hermes shall be turned to profit.