Page "Necessity" Paragraph 3

As a matter of political expediency, states usually allow some classes of person to be excused from liability when they are engaged in socially useful functions but intentionally cause injury, loss or damage.

For example, the fire services and other civil defence organizations have a general duty to keep the community safe from harm.

If a fire or flood is threatening to spread out of control, it may be reasonably necessary to destroy other property to form a fire break, or to trespass on land to throw up mounds of earth to prevent the water from spreading.

These examples have the common feature of individuals intentionally breaking the law because they believe it to be urgently necessary to protect others from harm, but some states distinguish between a response to a crisis arising from an entirely natural cause ( an inanimate force of nature ), e. g. a fire from a lightning strike or rain from a storm, and a response to an entirely human crisis.

Thus, parents who lack the financial means to feed their children cannot use necessity as a defense if they steal food.

The existence of welfare benefits and strategies other than self-help defeat the claim of an urgent necessity that cannot be avoided in any way other than by breaking the law.

Further, some states apply a test of proportionality.

So the defense would only be allowed where the degree of harm actually caused was a reasonably proportionate response to the degree of harm threatened.

This is a legal form of cost – benefit analysis.