Starting with the general political tests of the immediate cause: the first of these are what we can call “ad hoc policy tests”. The idea is that, in each case they decide, the courts evaluate a set of guidelines if it has been determined that a defendant has actually caused harm prohibited by law. They can balance certain “social interests,” such as the need for deterrence, with certain “individual interests,” such as the injustice of surprising a defendant with responsibility (Edgerton 1924). The courts then decide where that balance leads. Whatever decision is taken on a case-by-case basis, it is then laid on “immediate” or “legal” grounds. These labels are only the conclusions of political balances; labels have nothing to do with causality in the ordinary or scientific sense (Green 1929). A second group of problems arises from an indeterminacy of the meaning of the criterion, not from difficulties in verifying the facts. There is a lot of vagueness in counterfactual judgments. The uncertainty lies in the specification of the possible world in which we should test the counterfactual (Cole 1964a, b; Lewis, 1973b). Let us suppose an accused negligently destroys a rescuer and a sailor drowns because he does not have one.
When we say, “Without the act of the accused destroying the lifeline,” what kind of world do we imagine? We know that we must eliminate the act of the accused, but what should we replace it with? A guardian of life who was alternately destroyed by the rough seas? A defendant who did not destroy the rescuer because he had already pushed the victim overboard when no one else was there to throw the rescuer to the victim? And so on. For the counterfactual test to be determined to provide one answer over another, we must assume that those using this test have the ability to specify a particular possible world that is “similar” to our real world, except that the defendant did not do in that world what it did in the real world. In a personal injury case, causation must be proven – meaning that it is not enough to prove that the defendant acted negligently. Negligence must be the cause of the plaintiff`s injuries. In tort, it must be established that the tortious conduct of the defendant caused or contributed substantially to the damage suffered by the plaintiff before the plaintiff could be held liable for that damage. In determining actual causation, courts apply the same “but for” test used in criminal cases: “Would the plaintiff`s injury have occurred but for the defendant`s tortious conduct (Barnett v Chelsea and Kensington Hospital Management Committee [1969] 1 QB 428)? However, this assessment is insufficient for cases of simultaneous or cumulative causes where the actions of two or more perpetrators are sufficient to cause the damage. If there is more than one possible cause, several tests can be applied. For example, did the defendant`s negligence significantly increase the risk of harm (Mc Ghee v National Coal Board [1973] 1 WLR 1)? Was the defendant`s breach of duty also a significant cause of the damage? One in five grounds is not sufficient to establish liability (Wilsher/Essex Area Health Authority, 1988, AC 1074). For causation to be established on a balance of probabilities, there must be at least a 51% probability that the defendant`s actions caused the damage (Hotson v East Berkshire Health Authority [1987] AC 750).
It is much more likely that the defendant`s fire was necessary to destroy the victim`s home in the same way it was destroyed, so the counterfactual test seems to work best in cases of simultaneous overdetermination with this fine approach to action. Sometimes the opposite situation leads to a novus actus, i.e. actual causation cannot be proven, but the court still wants to hold the defendant accountable. In Sindell v. Abbott Laboratories, 607 P.2d 924 (Cal. 1980), the plaintiff`s mother used diethylstilbestrol to prevent miscarriage. [9] The drug, which was subsequently withdrawn from the market, caused the respondent to develop a malignant bladder tumour due to its negligent production. [9] However, there were many manufacturers of this drug on the market. The manufacturer of the drug that caused the injury could not be determined with certainty. [10] The Tribunal held that the defendant was liable in proportion to its market share. [11] They departed from traditional notions of pure cause and adopted a “risk-based” approach to liability. The defendant was held liable for the risk that he contributed to the occurrence of the damage.
[11] It should be noted that a theory of risk is not a theory that, strictly speaking, is based on concepts of causation, because the person who caused the harm cannot, by definition, be identified with certainty. However, it shows that the legal concepts of causality are a complex mix of real causes and public policy ideas regarding the availability of remedies. In R v Miller [1982] UKHL 6, the House of Lords stated that a person who puts a person in a dangerous position, in this case fire, will be held criminally liable if he does not properly rectify the situation. A second unified view of causality in law is the oldest of these types of propositions. He understands causality as a metaphysical primitive. Causality is not reducible to any other type of thing or thing, so there is little analysis to be said about it, and so little that juries should be informed of it (Smith 1911). The only thing we can say is that the causal relationship is a scalar relationship, that is, a matter of degree. One thing may be more a cause of a particular event than another.
Given the scality of causality, the law need only draw the line of demarcation of responsibility somewhere on the scale that marks the degree of causal contribution. For questions that vary on a smooth continuum, it is notoriously arbitrary to choose an exact breakpoint; Where is the line between middle age and age, red and pink, bald and not bald or caused and not caused? This approach therefore adopts a reasonably vague line, below which the causal contribution to a given injury is ignored for the purposes of assessing liability. The defendant should only be liable for damage if the degree of its causal contribution to that harm has reached a magnitude that is not de minimis or “substantial”. This is the original test of the “essential factor” as articulated by Jeremiah Smith in 1911. To the general objection that the test tells us little, its defenders reply that it is a virtue and not a vice, because there is little to say about causality. Like hardcore pornography, causality is something we “can know when we see it” (Potter Stewart`s language on pornography in Jacobellis v. Ohio) without the need for general definitions and tests (Borgo 1979). Note that the essential factor test “solves” the overdetermination problem mainly because it doesn`t say enough to get you into trouble in such cases. This therefore allows our clear causal intuitions to come into full force in these cases.
The ad hoc nature of this solution becomes apparent when one sees how the first and second tortious restatements managed to salvage what they were able to salvage from the sine qua non-test: if an alleged causal factor is a necessary condition for the damage, then it is (among the restatements) in itself substantial. In other words, the necessary condition – hood is indeed sufficient for the cause. But the necessary condition – the hood is actually not necessary for the cause, so a factor may be essential, even if it is not a necessary condition. This amounts to using the necessary state test if it works, but if it gives counterintuitive results (as in cases of overdetermination), it should not be used, but rather relied on causal intuitions that are not based on counterfactual relationships. This is recognized in a recent revival of primitivism of both reformulations on causality, according to which one is explicitly tasked with finding either a counterfactual dependence on harm or a “real contribution” to that harm (Stapleton 2015). While it is possible to argue that causality in law has nothing to do with causality in science and everyday life (other than the use of the same word), such a view is very counterintuitive; There is certainly some relationship between the two concepts of causality. This leaves two more plausible views on this relationship. A strong vision of this relationship would be that the concepts are the same. The three unified tests of legal causation considered last, and the two aforementioned metaphysical views of immediate causality, would all make such a strong relationship plausible. A weaker view of this relationship would be to consider one part of the legal concept of causality—”cause in fact”—as the same as causality in science and everyday life, but to consider the other part—”immediate causality”—as the conclusions of political analyses that have nothing to do with anything that could be considered causality in an ordinary sense.