"Our responses are rooted in feelings: reward in gratitude, punishment in resentment. The latter is so prominent and automatic that we sometimes witlessly strike out at an inanimate object we have carelessly bumped into, as if the object were blameable and deserving of punishment. 'Resentment seems to have been given us by nature for defence, and for defence only. It is the safeguard of justice and the security of innocence,' Smith wrote in Moral Sentiments." Vernon Smith