The Vermont senator was speaking at a conference hosted by the Pontifical Academy of Social Sciences marking the quarter-century anniversary of the "Centesimus Annus," Pope John Paul II's encyclical reflecting on the state of global society in the wake of the the end of the Cold War.
Sanders took the opportunity to amplify the Catholic Church's teachings that reflect the political themes that have defined his presidential campaign.
"There are few places in modern thought that rival the depth and insight of the Church's moral teachings on the market economy," he said in his prepared remarks. Sanders then went about explaining how past popes and the current one have persistently served as a moral counterweight against the reckless impulses of deregulated capitalism.
The Vatican speech represented Sanders in his element — speaking about ethics and economics in broad strokes. It comes the day after a debate in which rival Clinton repeatedly gored him for his inattention to policy details. For Sanders, technical questions are secondary to grappling with broader moral challenges.
"The challenges facing our planet are not mainly technological or even financial, because as a world we are rich enough to increase our investments in skills, infrastructure and technological know-how to meet our needs and to protect the planet," he said. "Our challenge is mostly a moral one, to redirect our efforts and vision to the common good."
If Sanders considers himself a force for reorienting the public toward the common good, he made it clear he believes Pope Francis — with whom the senator did not actually meet on Friday — to be another one.
"I am told time and time again by the rich and powerful, and the mainstream media that represent them, that we should be 'practical,' that we should accept the status quo; that a truly moral economy is beyond our reach," Sanders said. "Yet Pope Francis himself is surely the world's greatest demonstration against such a surrender to despair and cynicism. He has opened the eyes of the world once again to the claims of mercy, justice and the possibilities of a better world."
"He is inspiring the world to find a new global consensus for our common home," he said.
The speech allowed Sanders to take aim at the obsessive focus on free markets that emerged in the West after the fall of the Soviet Union, and implicitly pointed to his own social democratic values as a third way between 20th century communism and free market capitalism.
"We are now 25 years after the fall of Communist rule in Eastern Europe. Yet we have to acknowledge that Pope John Paul's warnings about the excesses of untrammeled finance were deeply prescient," Sanders said. "Twenty-five years after Centesimus Annus, speculation, illicit financial flows, environmental destruction and the weakening of the rights of workers is far more severe than it was a quarter-century ago."
Insofar as Sanders trails Clinton in the delegate count by a very significant margin, his own bid to open up the idea of Scandinavian-style social democracy seems likely to come to an end soon. But his remarks on his fervent following among young voters hints that the end of his campaign is probably not the end of his movement.
"I see that hope and sense of possibility every day among America's young people," he said. "Our youth are no longer satisfied with corrupt and broken politics and an economy of stark inequality and injustice."