Law of Torts
The Standard of Care and Breach of Duty: The Reasonable Man, the Four Risk Factors, and the Professional Standard
Once a duty is established, the question becomes how much care it required and whether the defendant fell short. The standard is that of the reasonable man, and it is objective: not what this defendant thought was enough, but what a reasonable person in his position would have done. How much care that amounts to is fixed by four factors: the magnitude of the risk, the seriousness of the injury if it occurs, the cost and practicability of precautions, and the utility of what the defendant was doing. Three classes of defendant are judged differently: children, professionals, and persons who undertake a task requiring special skill.
The four risk factors with the case on each, the three qualifications, and the professional standard
1. The Reasonable Man
- The standard is objective. The defendant is judged by an external standard and not by his own, however conscientious he was.
- The reasonable man is not a paragon. He is a person of ordinary prudence, not of exceptional foresight or skill, and he is not expected to guard against every conceivable risk.
- He is placed in the defendant's position, with the defendant's knowledge and the circumstances the defendant faced, including the time available for decision.
- Personal characteristics are disregarded, with the three qualifications set out below. Inexperience, slow reflexes and a nervous disposition are no answer.
- Special knowledge is not disregarded. A defendant who knows of a particular danger is judged against that knowledge, and cannot fall back on what an ordinary person would not have known.
2. The Four Factors
📖 Bolton v. Stone [1951] AC 850 Facts The plaintiff was standing in the road outside her house when she was struck by a cricket ball hit out of the defendants' ground. The ball had cleared a fence seventeen feet above the pitch level, about a hundred yards from the batsman. Balls had been hit out of the ground about six times in the preceding thirty years, and no one had ever been injured. Held The club was not liable. Ratio The risk was so small that a reasonable man, careful for the safety of his neighbour, would have thought it right to disregard it. Where the likelihood of harm is very slight, a reasonable man is not required to take precautions against it. The magnitude of the risk, measured by the probability of harm occurring, is the first factor in fixing the standard. |
📖 Paris v. Stepney Borough Council [1951] AC 367 Facts The plaintiff was employed in a garage as a fitter. He had already lost the sight of one eye, which his employers knew. While using a hammer on a rusty bolt beneath a vehicle, a chip of metal flew into his good eye and blinded him completely. It was not the general practice to supply goggles for that work. Held The employers were liable. Ratio The gravity of the consequences to the particular plaintiff is a factor in fixing the standard. The employers knew that an injury which would cost an ordinary man the sight of one eye would cost this man his sight altogether, and a greater degree of care was accordingly required of them. It is the seriousness of the potential injury and not merely its probability that matters. |
📖 Latimer v. AEC Ltd. [1953] AC 643 Facts An exceptionally heavy rainstorm flooded the defendants' factory. Water mixed with an oily cooling agent on the floor, leaving the surface slippery when the water drained away. The defendants spread all the sawdust they had over the affected area, which covered most but not all of it. The plaintiff slipped on an uncovered patch and was injured. Held The defendants were not liable. Ratio The only further step that would have eliminated the risk was to close the factory, and the risk that remained was not such as to require so drastic and costly a measure. The cost and practicability of precautions is weighed against the magnitude of the risk, and a defendant is not required to take precautions out of proportion to the danger. |
The factor | What it asks | The case |
Magnitude of the risk | How probable was it that harm would occur? | Bolton v. Stone [1951] AC 850 |
Seriousness of the injury | How grave would the harm be if it did occur, to this plaintiff? | Paris v. Stepney Borough Council [1951] AC 367 |
Cost of precautions | What would it have cost, in money and inconvenience, to guard against it? | Latimer v. AEC Ltd. [1953] AC 643 |
Utility of the conduct | What social value attached to what the defendant was doing? | The emergency and rescue cases; greater risks are justified in saving life |
- The four factors are weighed together, and none of them is decisive on its own.
- The exercise is comparative. A very small risk of a very grave injury may require more care than a moderate risk of a trivial one.
- Utility works in the defendant's favour. A fire engine answering an emergency call is judged differently from a delivery van, because the object justifies a greater risk.
- And the standard is fixed at the time of the conduct, on what was then known. A defendant is not negligent for failing to guard against a danger that was not recognised at the time.
3. The Three Qualifications
How the standard changes | Why | |
Children | Judged by the standard of a reasonable child of the same age | It would be unreal to expect adult judgment of a child, and the same applies to a child's contributory negligence |
Professionals | Judged by the standard of the ordinary competent member of that profession | A person exercising a special skill is measured against those who share it, not against the ordinary man |
Those who undertake a skilled task | Judged by the standard of that skill, whether or not they possess it | A learner driver is judged as a competent driver, because the road user is entitled to expect competence |
- The third qualification is really an application of the objective standard, not an exception to it. A person who holds himself out as able to do a thing is judged by the standard of those who can.
- The professional standard is not that of the most eminent member of the profession. It is that of the ordinary competent practitioner exercising and professing to have that skill.
- A higher qualification may raise it. A specialist is judged by the standard of a specialist in that field.
4. The Professional Standard: Bolam and Bolitho
📖 Bolam v. Friern Hospital Management Committee [1957] 1 WLR 582 Facts The plaintiff was given electro convulsive therapy without relaxant drugs and without manual restraint, and suffered fractures. Medical opinion was divided both on the use of relaxants and on the desirability of restraint. Held The hospital was not liable. Ratio A doctor is not guilty of negligence if he has acted in accordance with a practice accepted as proper by a responsible body of medical opinion skilled in that particular art, even though other practitioners would have adopted a different practice. The existence of a body of opinion taking the contrary view does not establish negligence. |
📖 Bolitho v. City and Hackney Health Authority [1998] AC 232 Facts A child suffered brain damage after respiratory failure. The doctor had negligently failed to attend, but said that even if she had attended she would not have intubated, and a body of professional opinion supported that course. Held The claim failed on causation, but the House of Lords qualified Bolam. Ratio The body of professional opinion relied on must itself be capable of withstanding logical analysis. The court is not bound to hold a defendant not negligent merely because some practitioners would have done the same, if that practice cannot be logically defended. Bolam is therefore a defence and not an abdication of the court's function. |
- Jacob Mathew v. State of Punjab, (2005) 6 SCC 1 applied Bolam in India, and added that for criminal liability the negligence must be gross.
- Kusum Sharma v. Batra Hospital and Medical Research Centre, (2010) 3 SCC 480 restated the principles governing medical negligence in India, and cautioned against a standard so exacting as to encourage defensive medicine.
- An error of judgment is not by itself negligence. A doctor or other professional who makes a reasonable choice between courses that a responsible body would accept is not negligent because the outcome was bad.
5. Proving the Breach
⚠ Common practice is evidence, and it is not conclusive That the defendant did what everyone in his trade does is strong evidence that he was not negligent, and courts give it weight. It is not conclusive. A practice may itself be negligent, and where it cannot be logically defended the court will say so: that is the point of Bolitho, and it applies outside medicine as well. Conversely, departing from the usual practice is evidence of negligence and is not conclusive either, since a defendant may have had good reason to depart from it. The same caution applies to statutory standards and codes of practice: compliance is evidence of reasonable care, and breach is evidence of the want of it, but the question for the court remains what a reasonable person would have done in the circumstances. |
6. The Position Stated Shortly
1. The standard of care is that of the reasonable man, and it is objective.
2. The defendant is judged by an external standard and not by his own, however conscientious he was.
3. How much care is required is fixed by four factors: the magnitude of the risk, the seriousness of the injury, the cost of precautions, and the utility of the conduct.
4. Bolton v. Stone: a risk so small that a reasonable man would disregard it requires no precautions.
5. Paris v. Stepney Borough Council: greater care is owed where the consequences to this plaintiff would be graver.
6. Latimer v. AEC Ltd.: precautions out of proportion to the risk are not required.
7. Children are judged by the standard of a reasonable child of their age, and professionals by the standard of their profession.
8. A person who undertakes a skilled task is judged by the standard of that skill, whether or not he possesses it.
9. Bolam: a doctor is not negligent if he acted in accordance with a practice accepted by a responsible body of medical opinion.
10. Bolitho qualifies it: that body of opinion must withstand logical analysis, and an error of judgment is not by itself negligence.