Free Riding on the Harm Principle

There are two main ways in which a mandatory vaccination policy is often defended-by accusing vaccine refusers of 'free riding', or by appealing to the 'harm principle'. In their recent book, Roland Pierik and Marcel Verweij take the latter approach-an attractive option, as they note, due to the wide acceptance of the harm principle. But in arguing that vaccine refusal should indeed be thought to constitute harm, they end up endorsing a very controversial version of the harm principle, which we should not automatically expect to secure widespread support. Steven Smith suggests that this (common) argumentative strategy amounts to free riding on the reputation of the harm principle, and is an inevitable consequence of invoking the principle as the foundation of an argument. In its most basic form, the principle is hard to resist. But in order to use it to justify a policy, you need to make some assumptions about what constitutes harm, which will lose you supporters along the way. In appealing to the wide appeal of the harm principle, Pierik and Verweij do not adequately recognise the controversial nature of their claims, and thus the need for stronger and more elaborate arguments in their support.