Metaphysical and absolute possibility

It is widely alleged that metaphysical possibility is “absolute” possibility (Kripke in Naming and necessity, Harvard University Press, Cambridge, 1980; Lewis in On the plurality of worlds, Blackwell, Oxford, 1986; van Inwagen in Philos Stud 92:68–84, 1997; Rosen, in: Gendler and Hawthorne (eds) Conceivability and possibility, Clarendon, Oxford, 2002, p 16; Stalnaker, in: Stalnaker (ed) Ways a world might be: metaphysical and anti-metaphysical essays, Oxford University Press, Oxford, 2003, pp 201–215; Williamson in Can J Philos 46:453–492, 2016). Kripke calls metaphysical necessity “necessity in the highest degree” (1980, p. 99). Van Inwagen claims that if P is metaphysically possible, then it is possible “tout court. Possible simpliciter. Possible period…. possib(le) without qualification (1997, p. 72).” And Stalnaker writes, “we can agree with Frank Jackson, David Chalmers, Saul Kripke, David Lewis, and most others who allow themselves to talk about possible worlds at all, that metaphysical necessity is necessity in the widest sense (2003, p. 203).” What exactly does the thesis that metaphysical possibility is absolute amount to? Is it true? In this article, I argue that, assuming that the thesis is not merely terminological, and lacking in any metaphysical interest, it is an article of faith. I conclude with the suggestion that metaphysical possibility may lack the metaphysical significance that is widely attributed to it.