Arvay told the court that his clients want the law changed to allow competent adults with irreversible medical conditions, and who are so disabled that they can't end their own lives, to ask a doctor to assist them in doing it.
That's ordinarily someone who can't move their arms or may not be able to swallow, he said, though he told the court that it would be up to Parliament to set the exact conditions under which a physician could help someone die.
The court last considered the issue in 1993 when it ruled that where assisted death is concerned, certain rights enshrined in the Charter of Rights and Freedoms are trumped by the principles of fundamental justice. In that case, Sue Rodriguez argued the existing laws violated her charter rights.
Rodriguez had Lou Gehrig's disease, a neurogenerative disease formally known as amyotrophic lateral sclerosis, or ALS.
In a 5-4 decision, the court ruled that while the laws did violate her rights, they were overridden by the principles of fundamental justice.
Twenty years later, right-to-die advocates say the legal and moral landscape in Canada has changed, and the laws need to change with it.
The court should find that there are new factors to consider, Arvay said, including last year's Bedford decision that he argued put the onus on the attorney general of Canada to prove the law is justified, rather than the onus being on those challenging the law, as it was when Rodriguez fought it.
Arvay argued his clients seek only to allow physician-assisted dying, not suicide assisted by others, because doctors want their patients to live, not die.
"We know that physicians will be reluctant gatekeepers and only agree to it as a last resort," Arvay said.
It's up to Parliament to define the restrictions on whatever a new law would allow, he said, with some guidance from the court as to what would be constitutional.
Sheila Tucker, who also represented the appellants, compared the desire for doctor-assisted suicide to a patient asking for their ventilator to be removed. Those patients may be disabled and may be depressed, she said, but it's a request society honours.
Tucker also disputed the notion that legalizing physician-assisted death would start down a slippery slope. The Supreme Court's 1993 decision came when the world was uncertain whether that would be the case, she said, but evidence from the European countries that allow assisted suicide show otherwise.
Nothing has changed
More than 20 years after the Rodriguez decision, the government is arguing that nothing has changed, in spite of the fact that the issue has been debated several times in Parliament.
Robert Frater, arguing on behalf of the federal government, said all life is valuable and the government aims to protect it.
Justice Rosalie Abella challenged Frater on the inequality of the law, asking why it's legal for able-bodied Canadians to kill themselves but not for those who aren't physically able to do it.
"We're not criminalizing it for those who are not able-bodied," Frater responded. "We abolished the attempted suicide attempt for everyone."
Abella said she finds it inconsistent to remove the offence from the Criminal Code "and yet leaving it essentially for those who are not able to commit suicide."
Several of the justices challenged Frater on his assertion that the trial judge overstepped her role when she evaluated some of the alternatives to the current law. Frater said the judge didn't show due deference to Parliament and its role in setting law.
Challenge rests on two charter sections
The British Columbia Civil Liberties Association launched what's become known as the "right to die with dignity" lawsuit in 2011 after B.C.'s Gloria Taylor set about ending her life following an ALS diagnosis.
In June 2012, the B.C. Supreme Court agreed that existing laws did deny Taylor the right to control her own life, and gave the court a year to write new ones.
At the same time, they gave her an exemption so she could get help ending her own life.
Taylor died before that could happen and the case was appealed to the Supreme Court.
The argument that assisted suicide prohibitions violate the charter rests on two sections: Section 7, which sets out the right to life, liberty and security of the person, and Section 15, which grants equality rights.