Metaphysical Indeterminacy

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This project is an investigation of metaphysical indeterminacy. We encounter the phenomenon of indeterminacy everywhere: from abstract puzzles to crucial ethical questions debated by doctors, politicians, and the public. When, for example, does a foetus become a person? Could we ever pinpoint the exact instant to the day, minute or second? Engaging the question at such a level of detail looks foolhardy at best. Instead, it seems that there is simply 'no fact of the matter' as to when the transition occurs. Yet if there is no determinate answer to such questions--if they are indeterminate--we must consider the broader implications.Indeterminacy is widely discussed by philosophers, but the dominant thought is that it must have one of two distinct sources: our ignorance of hidden facts or imprecision in how we use our words. Yet neither model fits the foetus case well. It is hard to believe that the indeterminacy here arises from ignorance--even knowing everything there was to know about embryonic development wouldn't solve the puzzle. Likewise, the case seems different from examples of indeterminacy that dominate the specialist literature-for example, how many hairs a man can have and count as 'bald'. Such cases show that we lack the required conventions of language--we just haven't decided the exact specifications of our term 'bald'. But it seems that mere linguistic conventions should not bear the weight of such morally significant matters as personhood. The puzzle, then, is that we could know everything about these cases, and decide exactly what we mean by the terms involved, yet still find indeterminacy. We argue that best diagnosis of this is that the indeterminacy here is due to what the world is like, not limitations in our knowledge or representation of the world. That is, the indeterminacy is metaphysical.And such metaphysical indeterminacy is not unique to personhood. We might think the future, for example, is indeterminate--there is no fact of the matter about what will happen 100 years from now. Similarly persistence: it may indeterminate whether my car is the same one that I bought from the shop after having so many parts replaced. Recent science even suggests that indeterminacy lies at the heart of fundamental physics. Metaphysical indeterminacy, however, has been unduly ignored--and as a result debates in the subject have been distorted by the apparent need to accommodate all cases of indeterminacy, no matter how intuitively unsuitable, to ignorance-based or linguistic accounts. Thus our primary goal is to develop a clear theory of metaphysical indeterminacy, specifically one which does not force philosophers to give up key logical or semantic principles. The first stage of the project asks: What does it mean to say that indeterminacy is metaphysical? We will challenge the widespread scepticism of the very notion by providing a detailed account of metaphysical indeterminacy, deriving fresh perspectives on the debate from other areas of metaphysics (e.g. time and possibility). We will compare our theory to its rivals, especially to positions which maintain that indeterminacy must be due to our own thoughts and practices.We will develop a detailed formal theory to model these ideas. Our previous work on indeterminacy's relationship to formal theories of possibility and time, and conditionality, shows great promise for creating a theory that, crucially, is compatible with classical logic.The final stage applies these investigations to cases which motivate the project. The investigators will each examine areas for the application of metaphysical indeterminacy: beginning and end of life puzzles (Williams); the 'unsettledness' of the future (Barnes); and metaphysical explanation (Cameron). These theoretical reflections have direct relevance to key moral problems - helping explain, for example, what it means when we say there is 'no fact of the matter' as to when a foetus becomes a person.