[This is the 7th in the series Religion and Science: A Beautiful Friendship.]

In this 7th part of the series, we take a look at some religious proverbs that have become woven into the fabric of civilization: the golden rule, "an eye for an eye, a tooth for a tooth," "turn the other cheek," and the idea of universal dignity.

"An eye for an eye" is best understood not as a formula for retribution or punishment, but rather as a simple descriptive model of how humans behave. When we're injured or abused, our immediate impulse is to do unto the perpetrator what's been done to us. We call it biblical justice. Often, victims of predation are not satisfied with merely getting even, but rather are inclined to "better the instruction," as Shylock points out in The Merchant of Venice. Escalation follows. Not to stand up to the perpetrator of a predatory act is to signal weakness and invite a follow-up that may bring death or enslavement.

It may be hard to tell who started a feud because the initial act of predation lies buried in a disputed past and escalation has since blurred the picture. A pattern of reciprocal indignities is what we see today in any number of ongoing conflicts around the world. At some point, it becomes more important to find a way to interrupt the cycle of revenge than to assign blame.

Attempts to stop cycles of predation by "turning the other cheek" can be suicidal unless they're part of a broad-based strategy of civil disobedience, and even then can result in great harm to