Step 1: Understanding the Concept:
The question is about the doctrine of 'Strict Liability' in the Law of Torts. Strict liability is a legal principle where a party can be held liable for damages or injury without proof of fault or negligence. It is applied in situations considered to be inherently dangerous.
Step 2: Detailed Explanation:
The doctrine of strict liability, famously laid down in the English case of Rylands v. Fletcher, applies to situations where a person is held liable even if they were not negligent. The core idea is that one who engages in certain types of activities does so at their own peril. Historically and in modern tort law, this principle applies to two main categories:
1. Keeping of dangerous animals: A distinction is made between animals that are dangerous by nature (\textit{ferae naturae}, like a lion or tiger) and animals that are normally harmless (\textit{mansuetae naturae}, like a dog or a cow). For the first category, the keeper is strictly liable for any harm caused. For the second, liability arises only if the keeper knew of the animal's dangerous propensity.
2. Abnormally dangerous activities: This is the principle from \textit{Rylands v. Fletcher}. It applies when a person brings onto their land and collects and keeps there anything likely to do mischief if it escapes. This is also referred to as a "non-natural use of land." Storing large quantities of water, gas, or explosives are classic examples.
Assault, battery, and negligence are distinct torts that generally require proof of intent or fault (breach of a duty of care), unlike strict liability.
Step 3: Final Answer:
The two broad categories for strict liability are the possession of certain animals and engagement in abnormally dangerous activities.