Fault may take the form of either intention, or negligence. It is required – in one form or another - for all common-law crimes. Common law crimes are those crimes which have been defined by our courts over time, including, murder, culpable homicide, assault, theft, fraud, robbery. Common law crimes may be contrasted with statutory crimes which are defined by the legislature. Of all common-law crimes, only culpable homicide and possibly contempt of court by a newspaper editor require fault in the form of only negligence. All other common law crimes require fault in the form of intention.
In general, common law crimes account for all serious crimes. However, the crime of rape is now the exception since it was abolished as a common-law crime and enacted under a reformed definition, as a statutory crime. Nevertheless, the crime of rape continues to require fault in the form of intention, as it did when it was a common law crime.
Also, in general, criminal liability is governed by the principle actus non facit reum, nisi mens sit rea. This may be translated as that an act does not render a perpetrator criminally liable unless he was conscious of its illegality. It means that conduct is not punishable unless it was accompanied by a guilty mind: No punishment without fault. It is abbreviated as mens rea (guilty mind) and is used to refer to the requirement that wrongful thought must accompany wrongful conduct.
While this principle reflects a strongly held value of the criminal justice system, and it may be regarded as the default position, our legislature has created crimes – as they are at liberty to do – which require no form of fault at all. These crimes are known as strict liability offences. Examples include certain traffic offences.
To understand these offences properly, one must understand that it is not that fault must be absent, instead fault is simply irrelevant. This means that whether or not one had intention or was negligent in respect of certain prohibited conduct, the prosecution does not have to prove any form of fault in order to obtain a conviction. This exception – of strict liability – to the principle that fault must accompany all wrongful conduct to attract criminal liability, continues in our law. It’s continued existence, is of course, however, subject to constitutional challenge.
Versari in re illicita
Historically, one other exception to the principle that fault is required existed in our law, under the doctrine of versari in re illicita - known as the versari doctrine. It is important to stress that this doctrine is no longer part of our law. It was rejected in 1962 in the case of S v Van der Mescht.
In terms of versari a person who engages in unlawful activity is criminally liable for all the unlawful consequences of this activity even though he or she does not harbor the required fault (intention or negligence) in respect of those consequences. Thus the purely accidental and innocent unlawful consequences of an unlawful activity were punishable.
Although the doctrine has been rejected from our law, it is important to consider how and when the doctrine applied in order to be able to identify an attempt to justify liability on versarian grounds. It is also important to be able to identify when liability would be versarian so that one may also know whether the imposition of criminal liability would not be versarian.
In the case of R v Wallendorf 1920 AD 383 the accused had assaulted a person. It transpired that the person was a policeman who was undercover. The accused did not know that the person he assaulted was a policeman. The evidence established that the accused was guilty of an assault upon the person of the policeman – as an ordinary person - and thus had engaged in unlawful activity. In addition, the accused was charged and convicted of the statutory offence of obstructing a policeman in the performance of his duty. The accused appealed citing the mens rea doctrine in his defence – that fault was required. The question before the court was whether, because the accused had been engaged in unlawful activity, he could be convicted of any unlawful consequence arising therefrom. The Court held, as follows:
"... whether or not the accused were aware of the fact that Mooney was a constable, they were guilty of committing an assault upon him... there may be sufficient proof of a guilty mind if it is shown that the accused intended to commit crime even though it be one different from that with which he is charged. In such a case the person who deliberately breaks the law must take the risk of his offence turning out to be of a more serious nature than he had intended."
In the case of R v Matsepe 1931 AD 150 the accused drove a truck negligently - that is, in the manner in which the reasonable person would not have – and collided with a tree. The accused did not know that a child had stowed away on the back of the truck. The presence of the child was thus not foreseen nor even reasonably foreseeable (in respect of negligence). therefore, in respect of the presence of the child on the truck and of the child’s death, the accused had no form of fault, neither intention nor negligence.
Nevertheless the accused was convicted of culpable homicide in the trial court. A question of law was reserved for the Appellate Division (now the Supreme Court of Appeal) concerning whether an accused could be found guilty of culpable homicide due to his negligence where it was found that the accused had no knowledge of the presence of the deceased at the time of the accident.
The court declared that:
“ … all the authorities were agreed that if a person is engaged in an unlawful act and kills another he is liable for culpable homicide...as the accused in driving as he did, was clearly engaged in an unlawful act, or at all events in doing a lawful act in an unlawful manner, it is no answer to say that he did not know or could not have known that the child was on the wagon.”
The relevance of this case is that despite the accused harboring no intention nor being negligent in respect of the child’s death he was nevertheless convicted of culpable homicide.
In 1962 however the versari doctrine was slated as outdated, out of step and obsolete and was abolished. In S v van der Mescht 1962 (1) SA 521 A the accused and another were in possession of unwrought gold amalgam which they sought to melt on a stove in order to extract gold. This possession was an offence in itself. The heating of the amalgam produced mercurial gases which fatally poisoned the accused’s accomplice and four children who were in the house at the time. The trial court convicted the accused of culpable homicide because he was negligent in not foreseeing the possibility of death. The Appellate Division held, by a majority, that the prosecution had failed to prove that the deaths were attributable to the accused’s negligence.
The question then arose whether the court was prepared to impose liability based on the versari doctrine. The Court (Steyn CJ, with Botha JA concurring, Hoexter JA dissenting) said the following – repeated at length here because of its importance:
“… the question is whether the Appellant was correctly convicted of culpable homicide purely on the basis that he caused the death of the deceased by his unlawful conduct, without negligence having been proved. Certain judgments of our courts, this court included [referring to Matsepe and Wallendorf], have decided this question in the affirmative ...
[Steyn CJ declared these judgments to have been wrongly decided].
I find it impossible, with respect, to reconcile myself with criminal liability based on the doctrine of versari in re illicita, where no proof of the accused's fault in regard to specific crime in question is required.... [T]he versari... doctrine is in any event and outdated legal concept which has for many years now been out of step with more contemporary views regarding criminal liability for offenses of which mens rea is an essential element...
[It is] in conflict with contemporary notions of justice, in cases where the absence of fault on the part of the perpetrator in regard to a prohibited consequence would otherwise preclude criminal liability....
The fact that the death of the deceased resulted from the commission by the appellant of an unlawful act, namely the unlawful melting of the amalgam, and does not justify, in the absence of fault on the part of the appellant vis a vis such a result, a conviction of culpable homicide. The appeal must accordingly succeed. The conviction and sentence are set aside.”
The versari doctrine was therefore abolished. There is one other case in the story of the demise of the versari doctrine, of which one should take account: S v Bernardus 1965 (3) SA 287 (A). This case is not important because it confirmed the judgement in Van der Mescht, abolishing versari, but because it may easily be misunderstood as reversing that decision – whereas it does not.
In S v Bernardus the accused had thrown a stick with a large knob on the one end (known as a “kierie”) at the deceased from a distance of about 9 to 11 paces away. The point of the stick (on the opposite end to the knob) penetrated the skull of the deceased by some 10 to 12 centimeters, killing him. It appeared on the facts that the accused had intended only to assault the deceased. The trial court however found the accused guilty of culpable homicide and the following question of law was reserved for decision by the Appellate Division:
"Is a person guilty of culpable homicide were he unlawfully assaults another and in so doing causes his death, but under circumstances in which he could not reasonably have foreseen the death?"
It should be noted that the question posed to the Appellate Division was whether it was correct to disregard the requirement of negligence, on the basis only that the consequence had arisen out of unlawful conduct for which the accused had the requisite fault.
Again the court, in emphasising that there can be no punishment without fault, rejected the versari doctrine as outdated. The court found that the intention in respect of an assault could not be regarded as a substitute for negligence in respect of death (for culpable homicide) without violating the principle of no punishment without fault - the principle of mens rea.
The court did however confirm the conviction and punishment for culpable homicide of the accused, not on the basis of versari, but on the basis that it regarded the accused as having actually been negligent in respect of the deceased's death.
Thus versari as an exception to the requirement of fault was abolished in 1962 in van der Mescht, which was confirmed in 1965. The remaining exception – of strict liability – however, continues to apply.
 S v Harber 1988 (3) SA 396 (A). It is not clear whether this position will be permitted to prevail under the Constitution.
 Criminal Law (Sexual Offences and Related Matters) Amendment Act 32 of 2007.
 Our courts are a hostile to strict liability and will only deviate from the principle of no liability without fault if there are clear and convincing indications (S v Arenstein 1964 (1) SA 361 (A); S v Qumbella 1966 (4) SA 256 (A).
 Subject to the constraints imposed by the Constitution.
 S v van der Mescht 1962 (1) SA 521 A.
 As will be seen in the context of mistakes, the identification of versarian liability plays a central role