Brief of R v Instan

Brief of R v Instan by Legum

R v. Instan (1893) 1 QB 450

Material Facts:

At some point, Instan was cared for by her 73-year-old aunt, whose death gave rise to the present case. Before her death, she contracted gangrene, which rendered her immobile and incapable of adequately taking care of herself. Only Instan knew about her aunt’s condition, yet she failed to take care of her, inform anyone of her ill health, or procure any medical assistance for her aunt. There was evidence that Instan took food supplies using the defendant’s money yet gave none to the deceased.

Her aunt consequently died, and Instan was charged and convicted of manslaughter because her neglect substantially accelerated the death of her aunt. She appealed against this conviction.


Whether or not the defendant had any legal duty to provide necessaries of life to the deceased, failure to do so would make her guilty of manslaughter owing to such failure accelerating the death of the deceased.

Arguments of the Defendant (Instan)

That the defendant was under no duty to provide the necessaries of health and life to her aunt, as such a duty could only arise out of statute, a contract, or common law. But in the present case, there was none.


That there was a common law duty imposed on the appellant which she failed to discharge. Her conviction for manslaughter, therefore, ought to be upheld.

Ratio Decidendi:

Per Lord Coleridge,

We are all of opinion that this conviction must be affirmed. It would not be correct to say that every moral obligation involves a legal duty; but every legal duty is founded on a moral obligation. A legal common law duty is nothing else than the enforcing by law of that which is a moral obligation without legal enforcement. There can be no question in this case that it was the clear duty of the prisoner to impart to the deceased so much as was necessary to sustain life of the food which she from time to time took in, and which was paid for by the deceased's own money for the purpose of the maintenance of herself and the prisoner; it was only through the instrumentality of the prisoner that the deceased could get the food. There was, therefore, a common law duty imposed upon the prisoner which she did not discharge. Nor can there be any question that the failure of the prisoner to discharge her legal duty at least accelerated the death of the deceased, if it did not actually cause it.

There is no case directly in point; but it would be a slur upon and a discredit to the administration of justice in this country if there were any doubt as to the legal principle, or as to the present case being within it. The prisoner was under a moral obligation to the deceased from which arose a legal duty towards her; that legal duty the prisoner has wilfully and deliberately left unperformed, with the consequence that there has been an acceleration of the death of the deceased owing to the non-performance of that legal duty. it is unnecessary to say more than that upon the evidence this conviction was most properly arrived at


As a general rule, failing to act to avert an injury is not grounds for criminal liability. However, failing to act when there is a duty to act may constitute the actus reus for a criminal offence. In the present case, there was a duty to act, but the appellant failed to act.