impossibility

That which, in the constitution and course of nature or the law, no person can do or perform. Impossibility is of the following several sorts: An act is physically impossible when it is contrary to the course of nature. Such an impossibility may be either absolute, i.e., impossible in any case, (e.g., to stop earth rotation) or relative (sometimes called "impossibility in fact"), i.e., arising from the circumstances of the case (e.g., for A. to make a payment to B., he being a deceased person). To the latter class belongs what is sometimes called "practical impossibility," which exists when the act can be done, but only at an excessive or unreasonable cost. An act is legally or juridically impossible when a rule of law makes it impossible to do it; e.g., for A. to make a valid will before his majority. This class of acts must not be confounded with those which are possible, although forbidden by law, as to commit a theft. An act is logically impossible when it is contrary to the nature of the transaction, as where A. gives property to B. expressly for his own benefit, on condition that he transfers it to C.

See also legal impossibility