The basic political principle of the Objectivist ethics is: no man may
initiate the use of physical force against others. No man—or group or
society or government—has the right to assume the role of a criminal and
initiate the use of physical compulsion against any man. Men have the right to
use physical force only in retaliation and only against those who initiate
its use. The ethical principle involved is simple and clear-cut: it is the
difference between murder and self-defense. A holdup man seeks to gain a value,
wealth, by killing his victim; the victim does not grow richer by killing a
holdup man. The principle is: no man may obtain any values from others by
resorting to physical force.