Impossibility may refer to:

Philosophy and logic

* Epistemic impossibility, in modal logic a statement that cannot be true, given what we know * Subjunctive impossibility, types of statement that cannot be true based on various types of subjunctive modality ** Logical impossibility, a statement that contains a logical contradiction * Impossible world, a concept in philosophical logic

Other uses

* Impossibility of performance, in contract law an excuse for non-performance of a contract *

Impossibility defense An impossibility defense is a criminal defense occasionally used when a defendant is accused of a criminal attempt that failed only because the crime was factually or legally impossible to commit. Factual impossibility is rarely an adequat ...

, a criminal defense for a crime that was legally impossible to commit *

Proof of impossibility In mathematics, an impossibility theorem is a theorem that demonstrates a problem or general set of problems cannot be solved. These are also known as proofs of impossibility, negative proofs, or negative results. Impossibility theorems often reso ...

, in mathematics a proof that demonstrates that a particular problem cannot be solved

Philosophy and logic

Other uses

See also