This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
The term "impossibility," like so many other terms of our law, is not in its origin a technical legal term, but it is a term taken over from popular usage and employed in the law in a variety of meanings, varying from its original popular meaning to a highly technical legal meaning, which, however, it is difficult to define in abstract terms.1 This is one of the characteristics of our unfortunate legal nomenclature;2 but the difficulties which are always caused by so lax a use of technical legal language are perhaps more marked in the use of this term than in the use of most of the other terms, since, in many of the other terms which are carried over from ordinary use, the popular meaning has frequently been superseded by the technical meaning, at least in the usage of the courts and the text-writers, while in the case of this term the popular meaning survives in ordinary language and is frequently employed by the courts.
1 See Sec. 2668 et seq.
2 See Sec. 56.
In its ordinary meaning, impossibility is practically synonymous with impracticability. It means the quality of being impossible; and "impossibility" is frequently defined as insuperably difficult in view of the circumstances. In this sense of the term, the ability of the person who is attempting to perform, together with the special circumstances of the case, is the test for determining whether the thing is impossible or not. In law the term "impossibility" is frequently used in this sense, but it is then said that impossibility has no effect upon the contract.3 If impossibility is used as indicating a state of facts which operate to prevent the contract from coming into existence, on the one hand, or which operate as a discharge of an existing contract, on the other, it is ordinarily used without any reference to the actual ability of the specific individual whose obligation to perform is in question; and the facts which are regarded as creating impossibility are, at the very least, facts which would prevent any one, no matter what his actual ability, from performing such obligation. In this connection, however, it may be added that even facts of this sort are frequently regarded by the courts as falling short of impossibility, in the sense in which the term is used to indicate that the contract does not come into existence, on the one hand, or is discharged, on the other.4
While the term impossibility is ordinarily used without any qualifying adjectives, it might be suggested that if the courts are to continue to use the term impossibility as applying to facts which do not affect the contract as well as to facts which do affect it in some way, the former class of facts might be called inoperative impossibility, while the latter class of facts might be called operative impossibility. No such distinction is ordinarily made, however; and the term impossibility is used without qualification, both of the operative and of the inoperative facts.