When faced with an urgent and credible threat of grave harm, we should take proportionate precautions. This maxim captures the core commitments of the “precautionary principle”. But what is it for a precaution to be “proportionate”? I construct an account of proportionality (the “ARCANE” account) that consists of five fundamental conditions (absolute rights compatibility, reasonable compensation, consistency, adequacy and non- excessiveness) and a tie-breaker (efficiency). I apply this account to two examples from the COVID-19 pandemic (border closures and school closures), (...) arguing that my account captures the key questions on which it is both feasible and important to integrate expert input with democratic input. I close by considering how we might try to manage the risk of future pandemics in a proportionate way. (shrink)

A sketch of my ethical views, or secular moral philosophy. Emphasis is on stating how it all hangs together.