In philosophy and modal logic, epistemic possibility relates a statement under consideration to the current state of our knowledge about the actual world: a statement is said to be: epistemically possible if it may be true, for all we know epistemically necessary if it is certain, given what we know epistemically impossible if it cannot be true, given what we knowEpistemic possibility is often contrasted with subjunctive possibility, and although epistemic and subjunctive possibilities are often expressed using the same modal terms or similar modal terms that are sometimes confused, statements that are qualified in terms of epistemic possibility and statements that are qualified in terms of subjunctive possibility have importantly different meanings. Wikipedia