Reasonable: the keystone of negligence.

Abstract

The concept of reasonableness is the golden thread which runs through the law of negligence, tying together all the disparate elements of duty, right, harm and injury into one coherent whole. It is the principle upon which the legal duty not to harm one's neighbour is based and it is the principle that ties that legal idea to particular fact situations. It is of fundamental import to the law. A claim for damages based on negligence is a claim to be compensated for an injury caused unintentionally, and consequently the law must find some other justification for holding a person liable than that person's wrongful intent (which is the justification for intentional wrongs). That justification emerges from the concept of reasonableness. If a person injures another but does so unintentionally he can be held legally liable therefor if he has acted unreasonably. So a claim for negligence against the doctor is not an accusation that he or she has intentionally injured a patient but that he or she has caused injury by his or her failure to act reasonably. Therefore, it becomes of fundamental importance to determine what the law demands in the way of reasonable behaviour. As a sort of judicial anthropomorphisation of the standard of behaviour expected and demanded, the law concerns itself with 'the reasonable man', that 'excellent', as A P Herbert describes him, 'but odious character'. The courts have been painting the portrait of this amorphous individual for over a century, and have produced divers and diverse descriptions therefor: Quot iudices tot sententiae. The reasonable man is the man on the Clapham omnibus, or the man in the street, the man 'who takes the magazines at home and in the evening pushes the lawnmower in his shirt sleeves'. 'The reasonable man goes round in bogey because he plays the orthodox shots, is never in trouble and is not called upon to do the unexpected'(l). He is the ordinary normal man, the classic juryman of a previous age, middle-class, middle-management, middle-aged and invariably male.