terial than another in modern business dealings. "In the
contracts of merchants time is of the essence," as the Supreme Court of
the United States has said in our own day. Certain ancient rules
restraining the apparent literal effect of common provisions in
mortgages and other instruments were in truth controlling rules of
policy. New rules of this kind can be made only by legislation. Whether
the parties did or did not in fact intend the obligation of a contract
to be subject to unexpressed conditions is, however, a possible and not
uncommon question of interpretation. One class of cases giving rise to
such questions is that in which performance becomes impossible by some
external cause not due to the promisor's own fault; a similar but not
identical one is that in which the agreement could be literally
performed, and yet the performance would not give the promisor the
substance of what he bargained for; as happened in the "coronation
cases" arising out of the postponement of the king's coronation in 1902.
As to promises obviously absurd or impossible from the first, they are
unenforceable only on the ground that the parties cannot have seriously
meant to create a liability. For precisely the same reason, supported by
the general usage and understanding of mankind, common social
engagements, though they often fulfil all other requisites of a
contract, have never been treated as binding in law.

Illegality.

In all matters of contract, as we have said, the ascertained will of the
parties prevails. But this means a will both lawful and free. Hence
there are limits to the force of the general rule, fixed partly by the
law of the land, which is above individual will and interests, partly by
the need of securing good faith and justice between the parties
themselves against fraud or misadventure. Agreements cannot be enforced
when their performance would involve an offence against the law. There
may be legal offence, it must be remembered, not only in acts commonly
recognized as criminal, disloyal or immoral, but in the breach or
non-observance of positive regulations made by the legislature, or
persons having statutory authority, for a great variety of purposes. It
would be useless to give details on the subject here. Again, there are
cases where an agreement may be made and performed without offending the
law, but on grounds of "public policy" it is not thought right that the
performance should be a matter of legal ob