Knowing the Reality
If we assume that the realization of existence is meant for realizing unknown things, we implicitly assume that anything which exists is capable of being realized. Of course if there is something which we just speculate of, but does not exist in reality, then it cannot be realized. According to the law of excluded middle, anything we suppose, is either true or false; and exactly one of the two is a reality. So it should be feasible to know this reality, that is, whether our supposition is true or false! In this way we should be able to know whether or not some event took place even in the past. Thus we can have justification for certain historical events too! However the law of excluded middle is just an obvious claim about a thing: It does not help to find that thing. A lot of research work is essential to actually find the thing which being is though obvious.