Elias Moser (2021) takes on a challenging task. He aims to show that we can derive from Robert Nozick's natural rights theory, and its associated contractarianism, a justification for the lockdowns that governments have used to contain the current pandemic. Lockdowns have been controversial. They have provoked loud and vigorous complaints from some quarters that they deprive people, unnecessarily and unjustifiably, of several of their fundamental liberties1 and Nozick's Anarchy, State, and Utopia (1974), with its defence of the minimal state, is just the sort of text to which we might expect the protestors to turn for support. Showing that lockdowns can find a defence in the foundations of Nozick's libertarianism is therefore no mean task.

A commentator on Moser's argument might begin by challenging the Nozickian premises on which it depends. That is not a path I shall take. Nozick's thinking is highly controversial but, even if we dissent from it, there is much we can learn from his penetrating and intricate analysis of the issues we confront when we strive to reconcile people's liberties with the threats and insecurities they may face. He presents his analysis as part of hypothetical history that plots the way in which individuals might move out of a state of nature and into a minimal state while suffering no violation of their natural rights; in truth, however, much that he has to say in Part I of Anarchy, State, and Utopia has a much larger compass. It can be exploited for its relevance to issues arising in many other contexts including, as Moser shows, issues thrown up by the current pandemic. There is much that is original, inventive and insightful in Moser's application of Nozick's thought to the pandemic and, in commenting on it, I shall remain, as far as possible, within the parameters of Nozick's thinking.

Moser's main claim is that the critical factor that would and should persuade individuals to agree to lockdown, and to accept the sacrifices of liberty it entails, is fear.