Where two persons, being shipwrecked, have got on the same plank, but, finding it not able to save them both, one of them thrusts the other from
it, and he is drowned; this homicide is excusable through unavoidable necessity, and upon the great universal principle of self-preservation, which
prompts every man to save his own life in preference to that of another,
where one of them must inevitably perish.
Herbert Broom's 1845 example of the Latin maxim necessitas inducit privilegum quoad jura privata.