James Manwaring

Self-defence is traditionally said to contain a necessity requirement, according to which defensive force is lawful only if it is necessary. But the necessity requirement is formulated inconsistently, and these inconsistencies substantially alter the scope of the defence. This article explains these inconsistencies. It concludes that it would be preferable to abandon the necessity requirement altogether. This would not leave a problematic gap in the law, because necessity would remain an important consideration when judging whether any use of force was reasonable.

Many philosophers have raised difficulties for any attempt to proportion punishment severity to crime seriousness. One reason for this may be that offering a full theory of proportionality is simply too ambitious. I suggest a more modest project: setting a lower bound on proportionate punishment. That is, I suggest a metric to measure when punishment is not disproportionately severe. I claim that punishment is not disproportionately severe if it imposes costs on a criminal wrongdoer which are no greater than the costs which they intentionally caused to others. I flesh out the implications of this Lower bound by discussing how to measure the costs of crime. Methodologically, I claim that different costs should be compared by considering preferences. Substantively, I claim that many proportionality judgements undercount the costs of crime by focusing only on the marginal and not the average cost. I suggest that we may hold defendants causally responsible for their contribution to the costs of that type of crime.