FORZA MAGGIORE (Vis maior, vis divina, casus cui resisti non potest). — When the agent is in such conditions as to be unable to prevent the event, or to save himself without offending or allowing another’s right to be offended, he is said to act under *forza maggiore*. In *forza maggiore*, the agent’s right comes into collision with the right of an innocent person, and this collision is the effect of natural events or of third parties.
For there to be responsibility, as a general rule, a certain freedom is ordinarily a necessary presupposition, which in turn presupposes a choice; this is lacking in the case of an action performed under *forza maggiore*. The ecclesiastical legislator (can. 2203 § 2) and the Italian legislator (art. 45 of the Penal Code) treat together both the case of fortuitous event (*v.* CASO FORTUITO) and *forza maggiore*; indeed, the Italian legislator in the new Civil Code (arts. 1218, 1250) sometimes employs a single formula, which refers to the absence of fault (“cause... not imputable”) to indicate both events.
In fact, traditional doctrine customarily contrasts both fortuitous event and *forza maggiore* with responsibility for fault; some hold that the two expressions are synonymous, indicating the same phenomenon. But in themselves, fortuitous event and *forza maggiore* are, in the judgment of most, concepts that should be kept distinct, even though they share the common negative significance of absence of freedom and irresistibility. Much has been written about precisely where the distinction should be drawn, some seeking it in the extraordinary nature of the phenomena, which would make the event foreseeable (fortuitous event) or not (forza maggiore); others in the different origin of the phenomena determining the event, which may be natural (*forza maggiore*) or provoked by the act of a third party (fortuitous event); others in the unforeseeability or foreseeability combined with irresistibility, considering *forza maggiore* to be the accidental event that, although foreseeable, gives neither time nor means to avoid it, and fortuitous event to be the event itself unforeseen; others in the theory of knowledge, considering *forza maggiore* to be the movement of natural forces, and fortuitous event that which derives from something our experience cannot establish. For others, the same event may be called either fortuitous event or *forza maggiore*, depending on whether it is considered from the aspect of the uncertainty of its adversary or from the aspect of the action it exerts on a person’s will. Both phenomena have a character of inevitability, but the fortuitous event derives this fact from the unforeseeability of the event, whereas *forza maggiore* derives it from its irresistibility.
It must, however, be conceded that the two terms have perfect ethical and juridical equivalence. Both concern civil law insofar as they create a failure to perform, in which there is a failure to observe a duty of diligence or a violation of a right; they concern the ethical sphere and penal law insofar as they are causes that exclude the psychological element of sin and of crime: voluntariness.
For a more precise exemplification of how events caused by *forza maggiore* are considered in the fields of obligations and of canon and Italian penal law, *v.* CASO FORTUITO. What is said there applies perfectly to the case of *forza maggiore*.