Incommensurability and its Implications for Practical Reasoning, Ethics and Justice

If values conflict and rival human interests clash we often have to weigh them against each other. However, under particular conditions incommensurability prevents the assignment of determinable and impartial weights. In those cases an objective balance does not exist. The original thesis of this book sheds new light on aspects of incommensurability and its implications for public decision-making, ethics and justice. Martijn Boot analyzes a number of previously ignored or unrecognized concepts, such as ‘incomplete comparability’, ‘incompletely justified choice’, ‘indeterminateness’ and ‘ethical deficit’ – concepts that are essential for comprehending problems of incommensurability. Apart from problematic implications, incommensurability has also favourable consequences. It creates room for autonomous rational choices that are not dictated by reason. Besides, insight into incommensurability promotes recognition of different possible rankings of universally valid but sometimes conflicting human values. This book avoids unnecessary technical language and is accessible not only for specialists but for a large audience of philosophers, ethicists, political theorists, economists, lawyers and interested persons without specialized knowledge. Reviews This book is a rigorous treatment of a major question: Can there be rational decisions between options having incommensurable values? Challenging the view that incommensurability does not preclude rational choice, Boot details obstacles to choices between incommensurables and indicates how practical reasoning should accommodate them. In doing this he says much of value about justice, healthcare, punishment, and other major topics. – Robert Audi, John A. O'Brien Professor of Philosophy, University of Notre Dame It is hard to think of a more important practical question than whether there are irresoluble conflicts between values. Philosophers in recent years have made major advances in clarifying that question and developing answers to it, but their work is often technical. Martijn Boot is technically adept, but in this highly significant book makes his arguments in clear and engaging prose. He brings out the implications of incommensurability in various areas, as well as taking the debate forward on several fronts. – Roger Crisp, Professor of Moral Philosophy, St Anne's College, Oxfor

The Aim of a Theory of Justice

Amartya Sen argues that for the advancement of justice identification of ‘perfect’ justice is neither necessary nor sufficient. He replaces ‘perfect’ justice with comparative justice. Comparative justice limits itself to comparing social states with respect to degrees of justice. Sen’s central thesis is that identifying ‘perfect’ justice and comparing imperfect social states are ‘analytically disjoined’. This essay refutes Sen’s thesis by demonstrating that to be able to make adequate comparisons we need to identify and integrate criteria of comparison. This is precisely the aim of a theory of justice (such as John Rawls’s theory): identifying, integrating and ordering relevant principles of justice. The same integrated criteria that determine ‘perfect’ justice are needed to be able to adequately compare imperfect social states. Sen’s alternative approach, which is based on social choice theory, is incapable of avoiding contrary, indeterminate or incoherent directives where plural principles of justice conflict