In Leviathan Hobbes writes of ‘the privilege of absurdity; to which no living creature is subject, but man only’. Nothing could be more absurd, according to Hobbes’s way of thinking, than killing oneself – except perhaps killing oneself in order to kill others. War shows the law of self-preservation working itself out in practice: humans kill other humans because they fear being killed themselves. But if that is so then any type of warfare that involves certain death for the combatants will be self-defeating. Soldiers who sacrifice their lives in order to protect their comrades are committing suicide – an attitude that Hobbes, for whom a self-interested fear of death was the primary human motivation, could never account for. Behaviour of this kind is not only irrational, but – Hobbes at times suggested – a symptom of madness.