Aggregation and Divisibility of Damage
Whether the harm for which compensation is sought in a action in tort is regarded as a single indivisible loss or a plurality of losses can have a number of important ramifications. If there are several losses, it may be that more than one of the claimant's interests is affected and that only some of his losses are considered to be recoverable damage. Whether or not consequential loss is regarded as an independent harm, to be addressed separately, or as part of the whole damage also bears upon this question of recoverability, as well as upon the application of statutes of limitation of action. Where there exist liability caps and minimum damage thresholds, the question may arise whether these apply once only, to the whole of the claim, or to each of several different components of the overall claim. A plurality of losses may also be reflected in the application of the laws of contributory negligence.
These problems relating to the divisibility of damage may be particularly pressing in cases where there are multiple claimants or multiple defendants. If two or more claimants have rights over the same damaged property (e.g. as joint owners or as owner and licensee), whether they are regarded as having suffered the same loss or independent losses may have implications for the claims they can bring. Conversely, if two or more defendants concurrently injure a single claimant, how their individual liability is determined may turn (at least in part) on whether the claimant's injury is considered a single indivisible harm or a plurality of losses. A number of more specific questions arise here in respect of joint (or solidary) liability.
To deal with problems relating to the proof of causation in mass tort scenarios -- where, for example, it is clear that several independent wrongdoers have injured numerous different people, but it proves difficult or impossible to establish a causal nexus between individual defendants and individual claimants - some jurisdictions have developed exceptional rules which allow for the imposition of liability on the basis of the defendant's creation of a risk, whether or not it can be shown that the risk eventuated and caused harm. In English law, the Fairchild decision (Fairchild v Glenhaven Funeral Homes Ltd  UKHL 22) provides an example, as does the theory of "market share" liability developed in the United States. What is considered the nature of the damage in such cases, and whether or not it is divisible, are crucial questions.
Questions relating to the divisibility of damage also arise in private international law. If a single wrongful act or omission causes several losses in different jurisdictions, could this mean that a different tort law is applied to each several loss? In what circumstances might effects experienced in different jurisdictions be regarded as merely aspects of the same indivisible loss, and what would be the implications in private international law? Other similar questions could be posed here too.
The divisibility of damage may also have implications from the point of view of civil procedure, for example, in determining which national courts have jurisdiction, the appropriate forum within that jurisdiction, and the recovery of costs. Another issue here is whether a final judgment in, or settlement of, proceedings brought in respect of a given wrongful act or omission have the effect of barring subsequent claims in the event that the claimant should suffer further harm. Modern procedural forms which allow class or representative actions by or on behalf of multiple individuals may also require the court to consider the divisibility of the damage suffered.
These issues arising in respect of substantive and procedural tort law are mirrored by a set of issues relating to insurance law and practice.