What is revenge? A quick dictionary search tells us that it is to exact punishment or expiation for a wrong on behalf of, esp. in a resentful or vindictive spirit etc etc… But what do we care what it means?! When you get hurt you don’t immediately try to forget and forgive in a sane way. There is a dirty little part of minds that is standard to all human beings, some more than others. Some won’t show it unless provoked. Although many aspects of revenge resemble the concept of justice, we all know it could reach a point of depravity. But, as physics tells us, every action must have an equal and opposite reaction, so whenever you get cheated on, your normal reaction would be to give it back to them, right? The primitive sense of justice comes from the notion that a human life is a vulnerable thing, a thing that can be invaded, wounded, of violated by another’s act in many ways. Many believe that the punishment in revenge should be more than the original injury, as a punitive measure. The Old Testament says “an eye for an eye” (cf. Exodus 21:24), which suggests the only remedy is a counter invasion, equally deliberate, equally crucial. To truly right the balance, the retribution must be exactly, strictly proportional to the original violation.
It differs from the original act only in the sequence of time and in the fact that it is response rather than the original act a fact frequently hidden if there is a long sequence of acts and counteracts.