Acceptability is the characteristic of a thing being subject to acceptance for some purpose. A thing is acceptable if it is sufficient to serve the purpose for which it is provided, even if it is far less usable for this purpose than the ideal example. A thing is unacceptable if it deviates so far from the ideal that it is no longer sufficient to serve the desired purpose, or if it goes against that purpose. From a logical perspective, a thing can be said to be acceptable if it has no characteristics that make it unacceptable:We say that a theory Δ is acceptable if for any wff α, Δ does not prove both α and ¬α.
