Metaphysical Indeterminacy

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.

One theme emerging in commentary on the present economic crisis is the way that ill-conceived theoretical presuppositions of the models at the basis of the financial industry can lead to harmful practical effects. The assumption that human agents act in a self-interestedly rational way - where this is understood via a specific formal model of expected utility maximization - is a key issue in this debate. Some argue that this model entrenches a distorted analysis of agents' likely actions, and contributed to the economic crisis.

Theoretical work in philosophy is easily seen as abstract and without practical application. But the possibility of practical harms arising from misguided theoretical assumptions shows this to be misguided. It is true that philosophical investigations are often motivated by the intrinsic interest in the subject. But additionally, there is urgent need for conceptual clarity on the presuppositions of practical activity in many areas. Successfully implemented and disseminated, our work can form the backdrop for foundational criticism of prevailing orthodoxy, for the provision of alternative starting points for developing practical plans, and for informed public debate.

Specific examples:

Beneficiary: the medical profession and public debate.
Our work on metaphysical indeterminacy provides a new framework for thinking about life-and-death issues: rather than being artificially pushed to posit sharp cut-offs marking the beginning of life, or regarding it as a matter ultimately of convention, our work shows how we can develop a framework on which there is fundamental indeterminacy over such issues.

This is not merely of theoretical interest. It gives us a new way to approach the practical applied ethical issues: in what sense, and in what circumstances, is abortion permissible? In what sense, and in what circumstances, might it be permissible to remove life support? Public debate is impoverished when it is assumed that the only principled answers to these questions are extreme ones (e.g. that life begins at conception, or at birth).

Such quandaries are of vital interest to the public, and in particular to medical practitioners. Through medical ethics courses, taken by practitioners, Leeds ensures knowledge transfer to the medical profession. The work done in the project will provide the theoretical tools for colleagues within our department who teach and discuss vital ethical issues with practitioners on a daily basis. One of the co-Is, Elizabeth Barnes, publishes on applied ethics and teaches within the interdisciplinary ethics centre, so we can ensure that such knowledge is transferred.

Beneficiary: policy-makers, economists etc; the wider public.
One theoretical distinction (dating back to Knight and Keynes) is to distinguish between risk (involving quantifiable odds) and uncertainty (where it may be inappropriate to assign odds, due to the total absence of relevant information). Orthodox Bayesian representations of belief states in terms of classical probability functions do not allow for this distinction.

There is a strong formal connection between beliefs about indeterminate matters and representation of Keynesian uncertainties. Moreover, some authors (e.g. Levi) have suggested that the way to accommodate uncertainty within a Bayesian framework is to make the assignment of probabilities indeterminate (in a specifiable way).

As part of our investigation of the logic and semantics of indeterminacy, we will look at how indeterminate degrees of belief, and degrees of belief in indeterminate subject-matters, are to be represented. There is widespread interest in interdisciplinary research on such matters between decision theorists, economists, and others. We can contribute to the wider public debate on the theoretical presuppositions of orthodox models of human beliefs and beha