Most modern statutes providing for a defense of compulsion evolved from the common-law policy that a person, when faced with a choice between suffering death or serious bodily harm and committing some lesser crime, could not be punished for committing the lesser offense. LaFave and Scott have explained the rationale of this 'choice of evils' approach as follows: 'One who, under the pressure of an unlawful threat from another human being to harm him (or to harm a third person), commits what would otherwise be a crime may, under some circumstances, be justified in doing what he did and thus not be guilty of the crime in question. . . . The rationale of the defense is not that the defendant, faced with the unnerving threat of harm unless he does an act which violates the literal language of the criminal law, somehow loses his mental capacity to commit the crime in question. Rather it is that, even though he has the mental state which the crime requires, his conduct which violates the literal language of the criminal law is justified because he has thereby avoided harm of greater magnitude.' LaFave and Scott, Handbook on Criminal Law 374 (1972). ...