We have seen that the conditions of penal liability are sufficiently indicated by the maxim, Actus non facit reum, nisi mens sit rea. A man is responsible not for his acts in themselves, but for his acts coupled with the mens rea or guilty mind with which he does them. Before imposing punishment, whether civilly or criminally, the law must be satisfied of two things: first, that an act has been done which by reason of its harmful tendencies or results is fit to be repressed by way of penal discipline; and secondly, that the mental attitude of the doer towards his deed was such as to render punishment effective as a deterrent for the future, and therefore just. The first is the material, the second is the formal condition of liability. The mens rea may assume one or other of two distinct forms, namely wrongful intention or culpable negligence. The offender may either have done the wrongful act on purpose, or he may have done it carelessly, and in each case the mental attitude of the doer is such as to make punishment effective. If he intentionally chose the wrong, penal discipline will furnish him with a sufficient motive to choose the right instead for the future. If, on the other hand, he committed the forbidden act without wrongful intent, but yet for want of sufficient care devoted to the avoidance of it, punishment will be an effective inducement to carefulness in the future. But if his act is neither intentional nor negligent, if he not only did not intend it, but did his best as a reasonable man to avoid it, there can be no good purpose fulfilled in ordinary cases by holding him liable for it.
Yet there are exceptional cases in which, for sufficient or insufficient reasons, the law sees fit to break through the rule as to mens rea. It disregards the formal condition of liability, and is satisfied with the material condition alone. It holds a man responsible for his acts, independently altogether of any wrongful intention or culpable negligence. Wrongs which are thus independent of mens rea may be distinguished as wrongs of absolute liability.
It follows that in respect of the requirement of mens rea wrongs are of three kinds:
(1) Intentional or Wilful Wrongs, in which the mens rea amounts to intention, purpose, or design.
(2) Wrongs of Negligence, in which the mens rea assumes the less serious form of mere carelessness, as opposed to wrongful intent.
(3) Wrongs of Absolute Liability, in which the mens rea is not required, neither wrongful intent not culpable negligence being recognised as a necessary condition of responsibility.
We shall deal with these three classes of wrongs, and these three forms of liability, in the order mentioned.
SUMMARY.
| Liability | Civil | Remedial. | |
| Criminal | Penal. | ||
| Remedial liability: | |||
| Specific enforcement the general rule. | |||
| Exceptions: | |||
| 1. Non-actionable wrongs. | |||
| 2. Transitory wrongs. | |||
| 3. Continuing wrongs in which sanctional enforcement is more expedient than specific. | |||
| Penal liability | Its conditions. | ||
| Its incidence. | |||
| Its measure. | |||
| Conditions of penal liability | Material—Actus. | ||
| Formal—Mens rea. | |||
| The nature of an act: | |||
| 1. Positive and negative acts. | |||
| 2. Internal and external acts. | |||
| 3. Intentional and unintentional acts. | |||
| The circumstances and consequences of acts. | |||
| The relation between injuria and damnum. | |||
| 1. All wrongs are mischievous acts. | |||
| Wrongs | In which proof of damage is required. | ||
| In which such proof is not required. | |||
| 2. All mischievous acts are not wrongs. | |||
| Damnum sine injuria. | |||
| (a) Loss of individual a gain to society at large. | |||
| (b) Legal remedy inexpedient. | |||
| The place and time of an act. | |||
| The formal condition of penal liability. | |||
| Mens rea | Intention. | ||
| Negligence. | |||
| Wrongs | 1. Of Intention. | ||
| 2. Of Negligence. | |||
| 3. Of Absolute Liability (exceptions to the requirement of mens rea). | |||