particular or commutative justice deprives another of his strict right. Such a sin is called an injury, which may be defined to be the violation of the strict right of another against his reasonable will.
Such an injury is formal if it is committed knowingly and wilfully, otherwise it is material.
A personal injury is committed against rights which are intrinsic to the person, such as the right to life, liberty, good name, and honour. A real injury is committed against the property of another.
2. Personal injuries are treated of elsewhere under the Fifth and Eighth Commandments; here we consider more especially real injuries done to the property of another.
There are three different species of real injuries robbery, theft, and simple damnification. Robbery, besides injury to property, includes also a personal injury, which consists in violence offered to another by forcibly depriving him of what is his. Simple damnification is the causing of damage to the property of another without taking away any of that property. Theft is the secret taking away of the property of another against his reasonable will.
3. No action is an injury unless it is against the reasonable will of the injured person, scienti et volenti non fit injuria, according to the twenty- seventh rule of law in the Sixth Book of the Decretals. The reason is obvious; because a person may as a rule renounce his rights, and then an action contrary to them ceases to be a violation of justice. It is no longer a depriving another of what is his; it has ceased to belong to him. There are, however, some rights which are inalienable, and actions against these will be contrary to justice even if the party wronged give his consent. No one can validly renounce his right to life, and so the private killing of another, even with his consent, except in lawful self-defence, is always murder. Similarly, marital rights of married people are inalienable, and, even if the husband consent, a wife's adultery is always adultery. The maxim, then, must be understood of rights which the owner can validly forego, and it asserts that no injury is done by acting against rights which the possessor with full knowledge and with perfect freedom does forego.
