In logic, there’s a law called tertium non datur. The English name of the law is “the law of the excluded middle” (literally: no third (option) is given). The law states that any statement is either true or false. There’s no in-between.
The next 4 paragraphs go into some fairly technical logics; if you think that … https://westergaard.eu/2016/11/tertium-datur/