Necessary Beings is concerned with two central areas of metaphysics: modality--the theory of necessity, possibility, and other related notions; and ontology--the general study of what kinds of entities there are. Bob Hale's overarching purpose is to develop and defend two quite general theses about what is required for the existence of entities of various kinds: that questions about what kinds of things there are cannot be properly understood or adequately answered without recourse to considerations about possibility and necessity, and that, conversely, questions about the nature and basis of necessity and possibility cannot be satisfactorily tackled without drawing on what might be called the methodology of ontology. Taken together, these two theses claim that ontology and modality are mutually dependent upon one another, neither more fundamental than the other.
Hale defends a broadly Fregean approach to metaphysics, according to which ontological distinctions among different kinds of things (objects, properties, and relations) are to be drawn on the basis of prior distinctions between different logical types of expression. The claim that facts about what kinds of things exist depend upon facts about what is possible makes little sense unless one accepts that at least some modal facts are fundamental, and not reducible to facts of some other, non-modal, sort. He argues that facts about what is absolutely necessary or possible have this character, and that they have their source or basis, not in meanings or concepts nor in facts about alternative 'worlds', but in the natures or essences of things.
Bob Hale has taught at the University of Lancaster, University of St Andrews, University of Glasgow, and University of Sheffield. He is an Emeritus Professor at the University of Sheffield, and his main research interests are in the foundations of mathematics, and philosophy of logic and language. From 1997 to 1999 he was a British Academy Research Reader, and he was elected Fellow of the Royal Society of Edinburgh in 2000. In 2002-3 he was President of Aristotelian Society, and from 2009 to 2011 was a Leverhulme Major Research Fellow. He is a member of the editorial board of Philosophia Mathematica, and is author of Abstract Objects (Blackwell, 1987), co-editor of Reading Putnam (with Peter Clark; Blackwell, 1994), the Blackwell Companion to Philosophy of Language (with Crispin Wright; Blackwell 1997), and Modality: Metaphysics, Logic, and Epistemology (with Aviv Hoffmann; OUP, 2010); and co-author of The Reason's Proper Study (with Crispin Wright; OUP, 2001).