For example, the tort defence of consent is often expressed with the truncated Latin expression volenti non fit injuria, whereas the full expression rarely used but which hi-lights the meaning of the word scienter, is scienter et volenti non fit injuria.
In pleadings, it is used to allege that the other side conducted itself knowingly.
In the example of litigation for damages suffered as a result of a domestic dog attack, the plaintiff would allege scienter as to "habitually ferocious" character.
For wild animals kept in captivity (such as lions or bears), called animals ferae naturae, the common law presumes the owner's scienter of the danger the animal represents.
In 1874, Applebee v Percy, published at 9 LR CP 647, the British court wrote:
"A distinction has always been taken between animals which are by nature fierce and untameable, such as tigers and others ferae naturae, and those which are not in their general nature ferocious.
"If a man keeps an animal of the former class, and another is injured, the owner of the animal is liable without any evidence of a scienter; but, where the animal belongs to a class which is not habitually ferocious, it is necessary to shew that its owner has notice that it has on former occasions shewn symptoms of a disposition to bite mankind."
More recently, the British Columbia Supreme Court adopted these words from a 1997 Court of Appeal decision (Prasad v Wepruk, 2004 BCSC 578, published at canlii.org/en/bc/bcsc/doc/2004/2004bcsc578/2004bcsc578.html):
"The law with respect to the doctrine of scienter is relatively clear. The owner of a dog which bites another will not be liable simply for being the owner. Liability will only attach under the doctrine if ... three conditions ... have been satisfied: .... the plaintiff (not the defendant) must establish that the defendant was the owner of the dog, that the dog had manifested a propensity to cause the type of harm occasioned, and that the owner knew of that propensity."