That question will be central when the high court hears the emotionally charged case of a Nova Scotia woman, who was charged and subsequently acquitted of counselling to commit murder after she tried to hire an undercover RCMP officer to kill her husband.
Nicole Ryan was acquitted of the charge after a Nova Scotia Supreme Court trial judge accepted her argument that she had no other way out of an abusive 15-year marriage to a man who threatened her and her daughter.
The Nova Scotia Court of Appeal upheld the ruling, concluding that Ryan's marriage amounted to a "reign of terror."
The court heard that Ryan's husband, Michael, threatened her and her daughter repeatedly, including an incident when he took them to a remote spot to show them where he would bury their bodies.
"Mr. Ryan began his reign of terror by making it clear that he would be in control of the relationship and she would be subservient," the Nova Scotia appeal ruling stated.
"In short, we see a woman who, on the surface, appeared to have had choices. But, below the surface, we see a victim of abuse, who at the time of the 'crime' appeared to have been living in a state of terror … On the surface, this did not look like self-defence, but below the surface we see a much different picture."
The Public Prosecution Service of Nova Scotia is appealing the ruling, and has the support of the Ontario Attorney General, which has been granted intervener status.
They are lined up against the Canadian Association of Elizabeth Fry Societies and Women's Legal Education and Action Fund.
"The legal question before the Court is whether duress, or another criminal law defence, is available to abused women in the circumstances of Ms. Ryan," said Kim Pate, Elizabeth Fry's executive director.
Both sides disagree on whether the Nova Scotia appeal court erred when it extended the traditional legal defence of duress to the case.
In its landmark 1990 ruling, the Supreme Court recognized battered woman syndrome. It outlined how a woman in an abusive relationship who kills her partner can use the Criminal Code's self-defence provisions to argue for an acquittal.
But Nova Scotia prosecutors say the self-defence provisions and the defence of duress were erroneously conflated in this case.
"The Court of Appeal erred in law in holding that the defence of duress was conceptually available in the circumstances of this case," states the factum on behalf of Nova Scotia's prosecutors.
Ryan's lawyers argue that law excuses "morally involuntary conduct," and that she felt threatened by her abusive husband to the point of fearing for her own life and her daughter's.
"The judgment of the Court of Appeal demonstrates a careful, thoughtful approach to the concept of duress where the 'psychological entrapment' of a battered woman precludes any safe avenue of escape."