In order to not do evil it is necessary to first define what evil is.
I believe there are two categories of evil; fraud and violence. Fraud consists in deceptive acts such as cheating and lying. Violence involves the use of force to steal, murder, or injure someone's person or property. The threat of force, coercion, is also considered an act of violence and to be considered evil also.
Unfortunately in this world there are people that, for whatever reason, engage in antisocial acts of behavior and often resort to the various methods of evil listed above. Therefore men must inevitably resort to corresponding acts of violence to protect their person or property.
At this point it becomes necessary to separate acts of aggression versus act of defense. The acts above are commonly referred to as acts of aggression when initiated by an aggressor. Aggressive acts can never be justified if one is to commit oneself to doing no evil. Defending oneself from acts of aggression, however, is justified.
In future posts I will discuss whether or not governments are the most adequate method for defending against aggression (I obviously believe they are not) but for now I just wish to clarify my position on what constitutes evil and draw a distinction between aggression and defense.
I will also, using the definitions above, show how many people engage in evil without knowing it.
For a good read on libertarian legal philosophy with regards to aggression and property rights please read Murray Rothbard's essay on
Law, Property Rights, and Air Pollution.