The papers in this issue derive from a seminar planned by the Australian Catholic University (ACU) for its Rome campus. James McLaren, the ACU’s Pro Vice Chancellor for Research, and I were to co-direct the seminar in March of 2020 but had to cancel it when the covid-19 pandemic made travel unsafe. The seminar was planned as part of an international series of seminars that the ACU has sponsored in Global Ethics. This series in turn is linked with other seminars the new ACU Dianoia Institute in Philosophy has designed for the Rome campus.

The broad topic of the seminar was The Limits of Liberty, with the subtitle “The Freedom of Individuals and the Security of Nations.” The papers lie broadly within this theme. Their focus is not limited to pursuing this broad topic in the context of democratic societies, but these societies figure significantly in most of the papers as a context for discussing—among other things—liberty, equality, human rights, governmental authority and individual autonomy, and the pressing question of international responsibilities for violations of human rights. The issues explored in the papers range from problems as specific as gun rights in free societies to the question of cosmopolitan versus nationalistic values in such contexts as the deliberations of the United Nations Security Council. In broad terms, the papers contribute to political philosophy. They do this in relation to understanding both the appropriate criteria for governmental legitimacy in nation states and the ethical implications of globalization for international cooperation.

A special issue of this scope cannot be done without editorial help from the Journal, including that of its production team. Despite the load of papers that the editors—Wim Dubbink and Noah Lemos have had to deal with through regular submissions, they gave me good advice, and Lemos devoted considerable time to reviewing the papers himself even after anonymous review and revision. I would also especially like to acknowledge other contributions, both to the planning of the Seminar and, at least indirectly, to the quality of the papers in this issue. These other contributions came either in drafts that were not prepared for publication when the Seminar had to be canceled or in comments given to me or the authors whose papers appear in this issue. The authors in question—all of whom prepared drafts for presentation and commentary at the Seminar—are Richard Arneson (University of California, San Diego), Gillian Brock (University of Auckland), Karen Hanson (University of Minnesota), and Candace Vogler (University of Chicago). Other authors planned to present commentary papers at the Seminar and in some cases drafted comments on one of the published or planned papers are Katherine Dormandy (University of Innsbruck), Kevin Jung (Wake Forest University), Nikolaj Nottelmann (University of Southern Denmark), Tyler Paytas (ACU), Alan Torrance (University of St Andrews), and René van Woudenberg (Free University of Amsterdam).

I have also benefited from the advice and support of James McLaren and I would especially like to thank him for his work in preparing the Seminar and Wayne McKenna, the ACU’s Deputy Vice Chancellor for Research, for making the overall project possible as an international research project supported by his office. It has been a pleasure to work with both of them in my capacity as an ACU Professor Fellow.