56 Chapter 2Making a contract
Performing an existing duty
Sometimes, a person claims to have given as consideration a promise to perform an exist-
ing duty. Whether or not such a promise amounts to good consideration depends upon
how the duty arose in the first place. Three possibilities must be considered: first, that the
duty arose under the general law of the land; second, that the duty arose under a previous
contract with a third party; third, that the duty arose under a previous contract with the
same person.The duty arose under the general law
It is not good consideration to promise to perform a duty which is imposed by the general
law of the land.However, it is good consideration to promise to exceeda duty which has arisen under the
general law of the land.The duty arose under a previous contract with a different person
The same consideration can be given to two different people, so that two contracts are
validly created. The following case provides an example.Collins vGodefroy (1831)The claimant was subpoenaed to attend a trial and give evidence. This means that he had
a legal duty to attend the trial, this duty having arisen under the general law. The defendant
agreed to pay the claimant six guineas (£6.30) if he actually did attend the trial.
HeldThe claimant was not entitled to the payment of any money. He could not give as
consideration the promise to attend the trial. The general law of the land already obliged
him to do this.Glasbrook Bros vGlamorgan County Council (1925) (House of Lords)During a strike by coal miners the police were doing their best to protect collieries. The
defendants asked the police to provide extra protection for their colliery, by stationing
policemen on the colliery premises. The police superintendent in charge said that this
would not be necessary. However, 100 policemen were stationed on the colliery premises
when the defendants agreed to pay the wages of these policemen. After the strike the
defendants refused to pay the £2,300 bill for the policemen’s wages, arguing that the police
had provided no consideration.
HeldThe defendants had to pay the £2,300. The police had a duty to protect property
under the general law of the land. However, the extra protection provided was in excess of
that which the police were obliged to provide under the general law of the land. Providing
the extra protection therefore amounted to good consideration for the promise to pay the
policemen’s wages.