JESPER RYBERG is Professor of Practical Philosophy, University of Roskilde, Denmark. His recent books include The Ethics of Proportionate Punishment (Kluwer, 2004) and, as editor, The Repugnant Conclusion: Essays on Population Ethics (Kluwer, 2005). He has published in philosophical journals such as Philosophical Papers, Theoria, Philosophical Quarterly, Res Publica, Ethical Theory and Moral Practice and the Journal of Applied Philosophy.
THOMAS S. PETERSEN is Assistant Professor of Practical Philosophy, University of Roskilde, Denmark. He has published in journals such as Bioethics, Ethical Theory and Moral Practice, the Journal of Medical Ethics, and Theoria.
CLARK WOLF is Associate Professor of philosophy and director of the Bioethics Centre, Iowa State University, USA. His recent books include The Idea of a Political Liberalism (ed., Rowman & Littlefield, 2000). He has contributed to a large number of anthologies and has published in journals including Environmental Ethics, Ethics, Philosophical Studies and Ethics and the Environment
