What does it take for a necessity operator to capture an absolute as opposed to merely relative sense of necessity? Bob Hale (2013) delineates and formalizes three conceptions of absolute necessity, which he takes to be co-extensive, and to permit non-logical, absolutely necessary truths. We raise problems with Hale’s three conceptions of absolute necessity, both on their own terms and as regards the compatibility of all the features Hale wants them to possess. We show that Hale’s formulations are less informative than they may seem. They are all in important respects under-specified, and turn out to be highly sensitive to presuppositions which must be made in specifying them. Hale’s claim that his three conceptions are co-extensive is, consequently, at best misleading: They are co-extensive only if the required presuppositions align, and there is no obvious reason that they must align. We also show that, while the formulations can be specified in such a way as to leave room for non-logical necessities, they only do so if the required presuppositions are not of the sort Hale intends. Non-logical necessities only come out as absolute if non-logical senses of necessity are chosen to play roles that Hale wishes to reserve for logical necessities. The failure of Hale’s conceptions raises doubts about the possibility of defining absolute necessity in terms of other necessities.
Many philosophers wish to distinguish between senses of necessity which are absolute and those which are relative. Physical necessity, i.e. necessity given the actual laws of physics, is often taken to be relative. Even if certain physical outcomes could not be otherwise given the actual physical laws, these outcomes still could be otherwise if the physical laws were different. Supposing that the laws of nature are themselves contingent, it follows that a physical necessity is not…
Click here to download full article