A person cannot be held responsible for every consequence from the chain of events following his actions. It is, thus, evident that there needs to be a reasonable limit to the liability of the tortfeasor; consequences that are too remote for consideration cannot be taken into account.
Lord Wright, in Liesbosch Dredger v SS Edison , said,
"The law cannot take account of everything that follows a wrongful act; it regards some subsequent matters as outside the scope of its selection, because it is infinite for the law to judge the causes of causes, or consequences of consequences. In a varied web of affairs, the law must abstract some consequences as relevant not perhaps on the ground of pure logic but simply for practical reasons."
There were two competing viewpoints established in the 19th century:
Foreseeability as a Test of Remoteness
This view holds that the tortfeasor shall only be liable for the consequences that a reasonable man could have foreseen arising from their actions.
This test was used in Rigby v. Hewitt  and the Greenland v. Chaplin  cases.
In King v. Phillips , a taxi driver negligently reversed his taxi, thereby injuring a small child. The mother, who saw this incident from a distance, thought the taxi had run over her child, suffered a nervous shock. The court applied the test of foreseeability here. It held that the taxi driver was not liable for the nervous shock of the lady as he did not owe her a duty of care, and the nervous shock on her end was not reasonably foreseeable in these circumstances.
Directness as a Test of Remoteness
This test makes the tortfeasor liable for all the direct consequences that arose out of their actions, whether or not a reasonable man could have foreseen them.
This test's landmark judgment is in Re: An Arbitration between Polemis and Furness, Withy and Co.  There was a petrol spill from the plaintiff's ship, the Polemis, because of which there were petrol vapours in the hold. The stevedores employed by the charterers negligently knocked out a plank from staging in the hold. It knocked something and ignited a spark, which catalyzed by the petrol vapours that destroyed the whole vessel. The fire was seen as a direct consequence of the stevedores' negligence, and since they worked under the charterers, the charterers were held liable for all the damage thus caused.
In Scott v. Shephard's Case , the tortfeasor launched a lighted squib into a crowd. In an attempt to protect themselves, they deflected the firecracker until it burst in the plaintiff's face and blinded him. Even though this injury was not foreseeable by the defendant, he was liable for all the injuries caused to the plaintiff.
Both these cases establish that the defendant is held liable for all direct consequences of their tortious actions.
The test of foreseeability is preferred over the test of directness. This preference was established in Overseas Tankship (UK) Ltd. v. Morts Dock & Engineering Co. , commonly known as the Wagon Mound Case No. 1.
In this case, large quantities of oil were negligently allowed to spill from a ship under the defendant's control. This oil spill spread to the plaintiff's wharf, where another ship was undergoing repairs. During welding operations, the oil caught on fire because of molten metal falling into it. This fire demolished the whole wharf along with the vessel that was under repair. Here, the Privy Council held that there was no means for the defendant to realize how big a fire the oil spill could have caused. Although the ship's destruction was a direct consequence of the oil spill, the defendant was not held liable for it as the test of foreseeability was applied here.
Hereon, the test of foreseeability was given preference over the test of directness. The Judicial Committee of the New South Wales Supreme Court, thus, discarded the Polemis case on the grounds that its judgement was not in consonance with their ideas of justice and morality.
There needed to be a consensus on what qualified as 'reasonably foreseeable in the context of negligence.' In Heson II , it was established that:-
"(A tort-feasor shall be liable) for any damage which he can reasonably foresee may happen as a result of the breach (of duty) however unlikely it may be, unless it can be brushed aside as far-fetched."
The Wagon Mound 2 Case  applies the limits of foreseeability established in the Heson II case to negligence and extends it to nuisance.
It was established in Cambridge Water Co. Ltd v. Eastern Countries Leather Plc  that even in strict liability cases, foreseeability of damages that are likely to arise from the escape of the dangerous this from the land was required to establish liability for the damage thus caused.
In Hughes v. Lord Advocate , the post office employees left a maintenance hole unattended when they went for their tea break after covering it with a tent surrounded by four kerosene lamps. While playing with one of the lamps, an eight-year-old boy fell into the maintenance hole, resulting in an explosion. The child suffered extreme burns. The House of Lords held that it was foreseeable that a child could sustain injuries while tampering with the lamp, but the explosion caused afterwards was not. Although the extent of the damage was not foreseeable, the defendants were still held liable but only to a limited extent of the damage.
In Doughty v. Turner Manufacturing Co. Ltd. , a factory worker accidentally knocked an asbestos-cement lid into a cauldron of hot acidic liquid. This caused a violent explosion, causing severe burns to the claimant standing close to the cauldron. Unknown to anyone, the asbestos-cement lining was saturated with moisture which caused the eruption to occur. After investigation of the accident, it was held that a reasonable man could not have anticipated this chemical reaction.
The golden thread running through the aforementioned cases is that they all relied on the Wagon Mound 2 Case to arrive at the concluding judgement that put the test of foreseeability to use.
However, there have also been cases that have been left untouched by the influence of the Wagon Mound cases.
In Smith v. Leech Brain & Co. Ltd , a worker suffered a burn on his lower lip because of the defendant's negligence. The burn developed into cancer, which resulted in his demise. The defendants were held liable for cancer that might never have developed if he had not suffered that particular burn injury. The test of directness had been at play here, which is a deviation from the trend of applying the test of reasonableness.
The judgement of the Smith Case was reiterated in Robinson v. Post Office , where a workman who slipped from a ladder owing to the negligence of the employer was given an ATS injection as a part of his treatment. The need for medical attention on the part of the workman was foreseeable. However, it was not foreseeable that the injection provided would cause encephalitis to the workman as he was found allergic to ATS. However, the post office was held liable as it was bound to take the victim as he was found.
There need to be lines of limits drawn for the liability incurred by negligence. It is not viable for a defendant to be liable ad infinitum for their tortious acts. Consequences that are too remote for reasonable consideration should, thus, be held outside the ambit of the defendant's liability.
 5 Ex. 240
 5 Ex. 243
 1 All E.R. 617
 3KB 560
 2 WBI 892
 1 All ER 404
 1 AC 350
 2 All ER 709
 1 All ER 53 (HL)
 UKHL 31
 AC 388
 2 QB 405
 1 WLR 1176