Courts were historically reluctant to recognize necessity caused by dire circumstances of peril as either an excuse or a justification. In R. v. Dudley,80men who killed a boy and resorted to cannibalism when lost at sea were convicted of murder. Noting that it was "the weakest, the youngest, the most unresisting" who was chosen to die, the court declared that any defence of necessity "appeared to us to be at once dangerous, immoral, and opposed to all legal principle and analogy." The Court conceded that the accused were subject to great suffering, but concluded:
We are often compelled to set up standards we cannot reach ourselves. . . . [A] man has no right to declare temptation to be an excuse, though he might himself have yielded to it, nor allow compassion for the criminal to change or weaken in any matter the legal definition of the crime.81The accused did not have a defence of necessity and they were convicted of murder. They were sentenced to death, but their sentences were commuted to six months’ imprisonment in an exercise of royal mercy by the Queen.
In the 1970s, necessity was pleaded as a defence to the crime of performing an abortion without the approval of an abortion committee. Dickson J. stated for the Supreme Court that the defence of necessity was "ill-defined and elusive," and concluded that if it did exist in Canadian law, "it can go no further than to justify non-compliance in urgent situations of clear and imminent peril when compliance with the law is demonstrably impossible." He added that "no system of positive law can recognize any principle which would entitle a person to violate the law because on his view the law conflicted with some higher social value."82Laskin C.J. dissented and would have left the defence with the jury, allowing it to decide whether there was an immediate danger to the woman’s life or health and whether it was certain that a legal and committee-approved abortion could be obtained to prevent that danger.
The Supreme Court finally recognized necessity as a common law defence in Perka,83which involved drug smugglers who were forced to
come ashore in Canada because of dangerous seas. Dickson C.J. was careful to restrict necessity to "circumstances of imminent risk where the action was taken to avoid a direct and immediate peril"; where the act was "morally involuntary" as "measured on the basis of society’s expectation of appropriate and normal resistance to pressure"; and where it was clear that there was no reasonable legal alternative to avoid the peril. The Court recognized necessity as an excuse for morally involuntary conduct but not as a justification that made conduct rightful. The idea that necessity excuses morally involuntary conduct now gives the common law defence a constitutional foundation, despite the fact that necessity was not recognized as a common law defence until 1984. In Ruzic,84the Supreme Court held that it was a principle of fundamental justice under section 7 of the Charter that a person who acts in a morally involuntary manner not be punished. In other words, those who commit an offence when there is no other realistic choice but to do so should not be punished because their actions are morally involuntary. This means that attempts by Parliament to abolish the common law defence, or perhaps even to restrict it by precluding its use for serious offences, would likely be found to violate the principle of fundamental justice that prevents the punishment of those who act in a morally involuntary manner.
Dickson C.J. stressed in Perka that necessity could only operate as an excuse in the face of immediate and urgent circumstances, and that it should not be based on "the comparative social utility of breaking the law against importing as compared to obeying the law."85In her concurring opinion, Wilson J. would have left open the possibility that necessity could operate as a justification. In such a scenario, an accused could have the defence, even though he or she did not act in a morally involuntary manner in the face of an emergency. Rather, the accused could deliberate and decide that the "fulfillment of the legal duty to save persons entrusted to one’s care is preferred over the lesser offences of trespass or petty theft."86The English Court of Appeal has recognized necessity as a justification to a deliberate and intentional killing in a case of the conjoined twins where it was certain that they would both
eventually die if they were not separated.87Whether necessity could be a justification as well as an excuse could have had a practical effect in the abortion context, where those who did not comply with the law had often made a deliberate decision to violate the law.
In R. v. Morgentaler,88the Ontario Court of Appeal held that the defence of necessity should not have been left to the jury when doctors were charged with violating a Criminal Code provision that required the approval of a hospital committee before an abortion was performed. The court stated that the doctors’ deliberate and planned decision to violate the law was inconsistent with the morally involuntary response to an immediate peril to life or health that was required for a necessity defence. The Supreme Court89did not deal with this issue because it decided that the law requiring approval of an abortion by a hospital committee was an unjustified violation of the rights of women under section 7 of the Charter.
The conceptualization of necessity as an excuse may preclude pre-mediated and deliberate decisions to violate the law. At the same time, it also precludes a "clean hands" argument that would deny the necessity defence to those who were engaged in illegal activity when they were faced with circumstances of urgent and compelling necessity. In Perka, the Court rejected the argument that an accused who is engaged in illegal conduct should be disentitled to the necessity defence. This decision meant that the jury could consider the defence, even though the accused had been engaged in drug smuggling when a storm forced them to land on Canadian territory. This followed from the Court’s conceptualization of the defence as an excuse that in no way justifies the conduct and the Court’s focus on whether the accused had any realistic choice but to commit the crime. Nevertheless, Dickson C.J. indicated that the defence of necessity would not apply "if the necessitous situation was clearly foreseeable to the reasonable observer, if the actor contemplated or ought to have contemplated that his actions would likely give rise to an emergency requiring the breaking of the law."90
In such circumstances, the defence would be denied, not because the accused was acting illegally, but because his or her conduct was not morally involuntary.
Necessity and duress are recognized in Canada only as excuses. Excuses have a self-defining feature because they are based on what
is required by a realistic concession to human weaknesses and do not normally involve a calculation of the respective harms that are avoided and harms that are inflicted.91Dickson C.J. elaborated that necessity conceptualized as an excuse "rests on a realistic assessment of human weakness, recognizing that a liberal and humane criminal law cannot hold people to the strict obedience of laws in emergency situations where normal...