A duty of care arises when the law recognises that one person owes another a responsibility to act carefully to avoid foreseeable harm.

Key case: Donoghue v Stevenson [1932] – established the “neighbour principle”:

You must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighbour, someone closely and directly affected by your actions.

This was refined in Caparo Industries plc v Dickman [1990], which set a three-part test for new situations:

• Foreseeability – Was harm to the claimant reasonably foreseeable?

• Proximity – Was there a sufficiently close relationship between claimant and defendant?

• Fair, just, and reasonable – Should the law impose a duty in the circumstances?

Once a duty exists, the court asks whether the defendant breached it by failing to meet the standard of care expected.

Standard of care:

That of a reasonable person performing the same activity (Blyth v Birmingham Waterworks Co [1856]).

Risk factors influencing the standard (Bolton v Stone [1951]; Paris v Stepney BC [1951]):

• Probability of harm – the greater the risk, the more care required.

• Seriousness of potential harm – more care owed where consequences are grave.

• Cost and practicality of precautions – unreasonable expense not required.

• Social utility – some risk justified if activity benefits society (Watt v Hertfordshire CC [1954]).

Professionals:

Measured against the standard of a reasonable professional in that field (Bolam v Friern Hospital Management Committee [1957]).

• Bolitho v City and Hackney HA [1998] added that professional opinion must withstand logical scrutiny.

Even if the defendant breached their duty, the claimant must show the breach caused the damage and that the damage was not too remote.

(a) Factual causation:

“But for” the defendant’s breach, would the harm have occurred? (Barnett v Chelsea & Kensington Hospital [1969]).

(b) Legal causation (remoteness):

The harm must be a reasonably foreseeable result of the breach (The Wagon Mound (No 1) [1961]).

• Only the type of damage must be foreseeable, not the exact way it happened (Hughes v Lord Advocate [1963]).

Intervening acts (novus actus interveniens):

A new, independent act can break the chain of causation if it makes the defendant’s conduct no longer the effective cause (Knightley v Johns [1982]).

The claimant must have suffered recognised damage — personal injury, property damage, or certain forms of financial loss.

• Pure economic loss (not arising from physical damage) is usually not recoverable unless caused by negligent misstatement (Hedley Byrne v Heller [1964]).

Psychiatric injury is recoverable if it is a recognised medical condition and satisfies specific tests (see Alcock v Chief Constable of South Yorkshire [1992]).

• Contributory negligence – Claimant’s own carelessness contributed to the harm; damages are reduced proportionally (Law Reform (Contributory Negligence) Act 1945).

• Volenti non fit injuria (consent) – Claimant knowingly and willingly accepted the risk (Morris v Murray [1991]).

• Illegality (ex turpi causa) – No claim arises from illegal conduct (Ashton v Turner [1981]).