We often say that something must be so (e.g. ‘It must be going to rain’). We also have ways of saying that, though something may not be the case, it could be (e.g. ‘It could rain tomorrow’). ‘Necessity and possibility: what will be must be?’ considers the notion of things that may happen, things that could happen, and modal operators (it is possible for something to be the case—so it is not necessarily the case that it is false). The argument for fatalism illustrates modal operators. Fatalism is the view that whatever happens must happen. We suppose that every situation comes furnished with a bunch of possibilities, or possible worlds.