Chair Murray Sinclair says the commission examining the impact of Canada's Indian residential schools is looking carefully at the 1455 and 1493 Catholic edicts as part of its final report.
Many argue the proclamations legitimized the treatment of aboriginal people as "less than human." Crown sovereignty in Canada can be traced back to those papal bulls and neither Canada nor the United States has repudiated them, Sinclair said.
"The movement to repudiation is very strong and is moving ahead," Sinclair said in an interview. "If we as the commission are going to join that movement or endorse it ... we have to come to a conclusion that it's necessary for reconciliation, to establish a proper relationship between aboriginal and non-aboriginal people."
A growing chorus in Canada is calling on the Vatican to help begin a new relationship with aboriginal people on equal footing.
The discovery bulls, and others in the same vein that followed, gave Catholic explorers "full and free power, authority, and jurisdiction of every kind" and outlined their "duty to lead the peoples dwelling in those islands and countries to embrace the Christian religion."
If aboriginal people refused, the Vatican granted its envoys the authority to enslave and kill.
If the commission recommends the bulls be rescinded, Sinclair said, it has to weigh the legal implications, which could strike at the core of Crown sovereignty over land.
"What would be the basis for rationalizing Crown sovereignty if the Doctrine of Discovery is no longer available?" Sinclair said. "We have to consider that question and perhaps give some direction about how that relationship can be re-established in a proper way ... on a nation-to-nation level."
The United Nations appointed a special rapporteur in 2009 who found the bulls lie "at the root of the violations of indigenous peoples' human rights." The edicts have resulted in the "mass appropriation of the lands, territories, and resources of indigenous peoples," the UN found. They also form the legal basis of many modern-day land claim disputes, it said.
The Canadian Conference of Catholic Bishops declined to comment on rescinding the bulls but pointed to the Vatican's written response to the UN in 2010. The church said the bulls didn't need to be officially revoked because they've already been nullified by more recent edicts.
One bull, from 1537, stated: "Indians and all other people who may later be discovered by Christians, are by no means to be deprived of their liberty or the possession of their property."
"Circumstances have changed so much that to attribute any juridical value to such a document seems completely out of place," the statement said.
An official revocation still matters to advocates like Keith Matthew. The former chief of Simpcw First Nation in British Columbia recently got the support of the Assembly of First Nations, which passed a resolution at its December meeting endorsing the revocation of the bulls.
It's about hitting the "reset button on our relationship," Matthew said.
"The papal bulls put us in a position no better than animals," he said. "We know better today. We're just as civilized and human as anyone else in this world. It's really about righting a historic wrong.
"I'm no animal. I'm a person, a human being."
Hayden King, director of the Centre for Indigenous Governance at Ryerson University, said simply calling for the edicts to be repealed isn't enough for reconciliation.
He said it would be more significant if the government recognized its sovereignty was based on a "fairy tale" that aboriginal people are not human and further recognized aboriginal title to land.
"Unless there was corresponding action, it would seem kind of hollow."