The doctrine or principle of impossibility, impossibility of performance or impossibility of performance of contract is a doctrine in contract law, and in this context, the "impossibility defense" is a defense offered against a claim for nonperformance.

In contract law, impossibility is an excuse for the nonperformance of duties under a contract, based on a change in circumstances (or the discovery of preexisting circumstances), the nonoccurrence of which was an underlying assumption of the contract, that makes performance of the contract literally impossible.

For example, if Ebenezer contracts to pay Erasmus £100 to paint his house on October 1, but the house burns to the ground before the end of September, Ebenezer is excused from his duty to pay Erasmus the £100, and Erasmus is excused from his duty to paint Ebenezer's house; however, Erasmus may still be able to sue under the theory of unjust enrichment for the value of any benefit he conferred on Ebenezer before his house burned down.

Sometimes it is impossible to perform a contract as a result of war.

The parties to a contract may choose to ignore impossibility by inserting a hell or high water clause, which mandates that payments continue even if completion of the contract becomes physically impossible.

Australia

Frustration usually involves impossibility of performance. As to whether the non-existence of the subject matter of a contract constitutes (initial) impossibility of performance, see McRae v Commonwealth Disposals Commission. Cf. Res extincta.

England and Wales

A contract may be frustrated by impossibility of performance.

In 1997, Downes said that impossibility and impracticability were separate in England and Wales, and that impracticability was not usually found to result in frustration.

The English case that established the doctrine of impossibility at common law is Taylor v Caldwell.

New Zealand

Wilkins and Davies Construction Co Ltd v Geraldine Corporation [1958] NZLR 985 is relevant.

South Africa

A contract may be ended by supervening impossibility of performance.

United States

At common law, for the defense of "impossibility" to be raised, performance must not merely be difficult or unexpectedly costly for one party, there must be no way for it to actually be accomplished. However, in the United States it is beginning to be recognized that "impossibility" under this doctrine can also exist when the contemplated performance can be done but only at an excessive and unreasonable cost, i.e., commercial impracticability. On the other hand, some US sources see "impossibility" and impracticability as being related but separate defenses.

See also

Notes

  • Roy Granville McElroy. Impossibility of Performance: A Treatise on the Law of Supervening Impossibility of Performance of Contract, Failure of Consideration, and Frustration. Cambridge, at the University Press. 1941.
  • Rudolf Gottschalk. Impossibility of Performance in Contract. Stevens & Sons Ltd. London. 1938. With a supplement for the years 1938–1944. Stevens & Sons. London. 1945.
  • "Impossibility and Mistake". Halsbury's Laws of England. Fifth Edition. Volume 9(1). Paragraph 888 et seq. Fourth Edition. Reissue. 1998. . Chapter 7. Paragraph 888 at page 644 et seq.
  • S Martin Leake. "Impossibility of Performance". A Digest of Principles of the Law of Contracts. Third Edition. Stevens and Sons. 1892. .
  • William R Anson. "Impossibility of Performance". Principles of the English Law of Contract. Sixth Edition. Oxford, at the Clarendon Press. 1891. Part 5. Chapter 4. Pages to 321.
  • Frederick Pollock. "Impossible Agreements". Principles of Contract. Fifth Edition. Stevens and Sons. 1889. Chapter 8. .
  • William T Brantly. "Impossibility of Performance". Law of Contract. Second Edition. M Curlander. 1912. Chapter 4. .
  • John D Lawson. "Discharge by Impossibility of Performance". The Principles of the American Law of Contracts at Law and in Equity. 1893. Chapter 13. .
  • John D Lawson. "Impossibility of Performance". Rights, Remedies and Practice. 1890. Volume 5. Chapter 119. .
  • Charles Fisk Beach. "Impossible Contracts". A Treatise on the Modern Law of Contracts.1897. Volume 1. Chapter 6. .
  • William Wait. "Impossible Contracts". A Treatise Upon Some of the General Principles of the Law. 1885. Volume 7. Chapter 32. .
  • Mindy Chen-Wishart. "Physical impossibility". Contract Law. Fifth Edition. Oxford University Press. 2015. Chapter 7.3.2. .
  • D J Joubert. "Physical Possibility of Performance". General Principles of the Law of Contract. Juta & Co Ltd. 1987. Chapter 13. Page 124.
  • Victor Goldberg. "Impossibility and Related Excuses". Framing Contract Law: An Economic Perspective. Harvard University Press. 2006. Chapter 19. .
  • John Henry Schlegel, "Of Nuts, and Ships, and Sealing Wax, Suez, and Frustrating Things - The Doctrine of Impossibility of Performance" (1968 to 1969) 23 Rutgers Law Review
  • John D Wladis, "Common Law and Uncommon Events: The Development of the Doctrine of Impossibility of Performance in English Contract Law" (1986 to 1987) 75 Georgetown Law Journal
  • "The Principle of Impossibility in Contract" (1940) 56 Law Quarterly Review
  • J Denson Smith, "Some Practical Aspects of the Doctrine of Impossibility" (1937 to 1938) 32 Illinois Law Review
  • Christopher J Bruce, "An Economic Analysis of the Impossibility Doctrine" (1982) 11 The Journal of Legal Studies
  • Richard A Posner and Andrew M Rosenfield, "Impossibility and Related Doctrines in Contract Law: An Economic Analysis" (1977) 6 The Journal of Legal Studies
  • "Impossibility of Performance" (1870) 49 The Law Times (20 August 1870)
  • Edwin W Patterson. "Impossibility of Performance and Frustration of Purpose". Cases and Materials on Contracts II. Foundation Press. 1935. . Chapter 3. Page 285.
  • George P Costigan. "Impossibility of Performance of Contracts". Cases on the Law of Contracts. . 1932. Chapter 8. Page 700.