Necessity is not truth in all possible worlds / A necessidade não é a verdade em todos os mundos possíveis

My main purpose in this article is to present an argument for the idea that necessity qua truth in all possible worlds, without other qualifications, leads us to contradiction. If we do not want to accept the contradiction, we will face a dilemma: or accepting that everything we take as contingent is in fact necessary, or accepting that we cannot translate some sentences – at least the indexed to worlds sentences – to the possible worlds vocabulary. We have an intuition – and we develop an argument for it – that if “P”, evaluated in w*, is a contingent truth, so it cannot be the case that “P in w*” is a necessary truth. Generally, the argument tries to show that “P”, evaluated in w*, and “P in w*” are made true by the same contingent fact. If we suppose that “P in w*” is necessary, we would have to suppose that the fact that makes it true is also necessary, which would be contradictory with the fact that makes “P” true in w*, if we accept that what makes “P” in w* and “P in w*” true is the same fact. I attain such an aim by presenting an argument that is divided in two parts, one to imply the contradiction and the other to show that there is no relevant difference between the indicated sentences, by showing how the dilemma arises, and by answering some possible objections. This is an important objective because the possible worlds vocabulary is the default vocabulary to treat the modalities of necessity and possibility. And if it is flawed, it is important that we identify the flaw and fix it – which is exactly what we intend to do at the end of this article, by suggesting some qualification at the necessity notion, that the necessity is the native truth in all possible worlds. And this would save the possible worlds vocabulary from the presented objection.