The test
The Two-Part Test
Capacity = appreciate wrongfulness + act accordingly.
Criminal capacity
Criminal capacity is the mental ability, at the time of the act, both (1) to APPRECIATE THE WRONGFULNESS of the conduct (the cognitive leg) and (2) to ACT IN ACCORDANCE with that appreciation — to resist the impulse and conduct oneself accordingly (the conative/volitional leg). If EITHER leg is absent, the accused lacks capacity and cannot be convicted.
Where capacity fits
Capacity is presumed. It is a separate enquiry from voluntariness (the act) and from fault. The main factors that may exclude capacity are: youth, mental illness, and (in a given case) intoxication or severe emotional stress.
Capacity = (1) ability to appreciate wrongfulness + (2) ability to act in accordance with that appreciation. Lose either leg and there is no capacity (Mahlinza).
Key Case — Capacity
S v Mahlinza1967 (1) SA 408 (A)Criminal capacity requires appreciation of wrongfulness and the ability to act accordingly; the mental-illness enquiry is fact-specific.
Facts. A mother, in a disturbed mental state, placed her infant children on a fire, killing one. Her criminal capacity — whether mental illness had deprived her of the ability to appreciate wrongfulness or to act in accordance with that appreciation — was in issue.
Legal question. How is criminal capacity assessed where mental illness is raised, and what is the nature of that enquiry?
Judgment. The Appellate Division emphasised that the enquiry into mental illness and criminal capacity is fact-specific, and dealt with the accused's mental state at the time of the killing.
Significance. An early leading statement on criminal capacity and mental illness, now framed by the test in s 78 of the Criminal Procedure Act 51 of 1977 (appreciation of wrongfulness + acting in accordance with that appreciation).
Exam tip. Use Mahlinza for the two-legged capacity test (appreciate wrongfulness + act accordingly) and the fact-specific nature of the mental-illness enquiry. Link it to s 78 CPA and the special verdict.
Mental illness
The Pathological Ward
Mental illness and the special verdict (s 78 CPA).
Pathological incapacity
Where a MENTAL ILLNESS or defect deprived the accused, at the time of the act, of the capacity to appreciate wrongfulness or to act accordingly, s 78 of the Criminal Procedure Act 51 of 1977 applies. The result is not an ordinary acquittal but the SPECIAL VERDICT — "not criminally responsible" — after which the court may order detention or treatment.
Onus and procedure
The party who raises the accused's incapacity by reason of mental illness bears the onus of proving it on a balance of probabilities (s 78(1B)). A panel may be appointed to enquire and report (ss 77-79).
Mental illness that removed capacity → the s 78 CPA special verdict ("not criminally responsible"), not a simple acquittal. Onus on the party raising it, on a balance of probabilities.
Exam trap: mental illness that excludes capacity is PATHOLOGICAL incapacity (s 78, special verdict). Do not confuse it with NON-pathological incapacity (below), which leads to an ordinary acquittal.
Youth
The Children's Gate
Age and criminal capacity under the Child Justice Act.
The age thresholds
Under the Child Justice Act 75 of 2008 (as amended), a child UNDER 12 years lacks criminal capacity entirely (an irrebuttable rule). A child aged 12 but under 14 is REBUTTABLY presumed to lack criminal capacity — the State must prove, beyond reasonable doubt, that the child had the capacity to appreciate wrongfulness and to act accordingly.
From 14
From the age of 14 a child is presumed to have criminal capacity, like an adult, though youth remains relevant to fault and to sentencing within the child-justice framework.
Under 12 = no capacity (irrebuttable). 12 to under 14 = rebuttable presumption AGAINST capacity (State must prove capacity). 14+ = presumed to have capacity.
Exam trap: the minimum age of capacity was raised to 12. For a child of 12 or 13, the State bears the burden of proving criminal capacity beyond reasonable doubt.
Intoxication & stress
The Intoxication Lane
Voluntary intoxication and non-pathological incapacity.
Voluntary intoxication
Voluntary intoxication is not, in itself, a defence, but it is judged by its ACTUAL EFFECT. Depending on its degree it may exclude voluntariness (no act), criminal capacity, or intention (Chretien, which rejected the rigid "specific intent" rule). Severe intoxication can therefore lead to acquittal of the crime charged.
The statutory offence
Because Chretien could lead to complete acquittals, s 1 of the Criminal Law Amendment Act 1 of 1988 created a separate statutory offence: committing a prohibited act while criminally incapable due to voluntary intoxication.
Non-pathological incapacity
Provocation or severe emotional stress may, in principle, exclude capacity — but this NON-pathological incapacity is equated with sane automatism and approached with great caution. Losing one's temper is NOT the same as losing capacity: a person who can control themselves but chooses not to acts with capacity (Eadie).
Intoxication is judged by its real effect on voluntariness/capacity/intention (Chretien); note the s 1 statutory offence (Act 1 of 1988). Non-pathological incapacity from provocation is equated with sane automatism and narrowly applied (Eadie).
Key Cases — Intoxication & Provocation
S v Chretien1981 (1) SA 1097 (A)Voluntary intoxication is judged by its actual effect on voluntariness, capacity or intention; the rigid specific-intent doctrine was rejected.
Facts. After a party, the heavily intoxicated accused drove his car into a group of people standing in the road, killing one and injuring others. He said he believed they would move out of the way.
Legal question. What is the effect of voluntary intoxication on criminal liability — can it negate voluntariness, criminal capacity or intention?
Judgment. The Appellate Division rejected the specific-intent approach and held that intoxication must be assessed for its actual effect on capacity and intention. Chretien's intoxication negated the intention required for the assault charges, and he was convicted of culpable homicide for the death.
Significance. The landmark case on intoxication. It led directly to s 1 of the Criminal Law Amendment Act 1 of 1988, which created a statutory offence of committing a prohibited act while criminally incapable through voluntary intoxication.
Exam tip. Chretien judges intoxication by its real effect (voluntariness / capacity / intention), not a fixed rule. Remember the legislative response: s 1 of Act 1 of 1988.
S v Eadie2002 (3) SA 719 (SCA)Non-pathological incapacity from provocation/emotional stress is equated with sane automatism; loss of temper is not loss of capacity.
Facts. In a road-rage incident the accused, after being provoked, beat another driver to death with a hockey stick. He raised the defence of non-pathological criminal incapacity due to provocation and emotional stress.
Legal question. Can provocation or emotional stress give rise to a defence of non-pathological criminal incapacity, and how does it relate to sane automatism?
Judgment. The SCA rejected the defence on the facts and narrowed it, equating non-pathological incapacity from provocation with sane automatism (genuinely involuntary conduct).
Significance. Curtailed the previously expanding provocation / emotional-stress defence and clarified that loss of self-control does not equal loss of criminal capacity. The leading modern authority.
Exam tip. Eadie limits the provocation defence: distinguish losing your temper (still voluntary, capacity intact) from genuine automatism (involuntary). Courts require strong objective support.