David Haines on the actual, possible and necessary
[W]hat does Heidegger mean when he uses these terms? When he explains what is meant by actual, he says, “the currently actual, which affects us and which we stumble upon: the happenings, the destinies and doings of man, nature in its regularity and its catastrophes, the barely fathomable powers that are already present in all motives and aims, in all valuations and attitudes of belief.” By actual he means what presents itself to us as present, not merely as mind-independent, but also, the present attitudes and beliefs. By possible he means, “the not yet actual.” He says that “The possible also ‘is’, its being simply has another character than the actual.” We are not told what he means by necessary, though it is likely that he simply means what must be.
With helpful venn diagrams.