Modal Logic as Metaphysics - Tapa dura

I am inclined to say that Modal Logic as Metaphysics is the greatest ever integrated study of the logic and the metaphysics of modality: it is almost certainly the most comprehensive. [It] is also, in my judgment, the most important book on the metaphysics of modality since On The Plurality of Worlds (John Divers, Philosophy and Phenomenological Research)

a very important addition to the literature... clear, meticulous, and ingenious... This tightly argued book contains a large number of interesting arguments, claims, observations, and comments on a wide variety of topics in modal logic and metaphysics. It reminds us that there is much useful philosophizing to be done beyond an incredulous stare. (Takashi Yagisawa, Notre Dame Philosophical Reviews)

the issues raised by the book are among the most important in current work on modal metaphysics, and I very much hope that all metaphysicians of modality make the effort required to come to terms with its many ideas and arguments. (M. L. Cresswell, The Philosophical Quarterly,)

Are there such things as merely possible people, who would have lived if our ancestors had acted differently? Are there future people, who have not yet been conceived? Questions like those raise deep issues about both the nature of being and its logical relations with contingency and change. In Modal Logic as Metaphysics, Timothy Williamson argues for positive answers to those questions on the basis of an integrated approach to the issues, applying the technical resources of modal logic to provide structural cores for metaphysical theories. He rejects the search for a metaphysically neutral logic as futile. The book contains detailed historical discussion of how the metaphysical issues emerged in the twentieth century development of quantified modal logic, through the work of such figures as Rudolf Carnap, Ruth Barcan Marcus, Arthur Prior, and Saul Kripke. It proposes higher-order modal logic as a new setting in which to resolve such metaphysical questions scientifically, by the construction of systematic logical theories embodying rival answers and their comparison by normal scientific standards. Williamson provides both a rigorous introduction to the technical background needed to understand metaphysical questions in quantified modal logic and an extended argument for controversial, provocative answers to them. He gives original, precise treatments of topics including the relation between logic and metaphysics, the methodology of theory choice in philosophy, the nature of possible worlds and their role in semantics, plural quantification compared to quantification into predicate position, communication across metaphysical disagreement, and problems for truthmaker theory.