Pope Leo XIV's first encyclical is a 42,000-word letter on artificial intelligence

In the halls of the 400-year-old St. Peter's Basilica of the Vatican, the focus on Monday was on a technology that's in its infancy.

Pope Leo XIV presented a more than 42,000-word letter on artificial intelligence in his first encyclical as pontiff.

The letter was subtitled "on safeguarding the human person in the time of artificial intelligence." Its title, the Latin phrase, "Magnifica humanitus" -- Magnificent humanity.

Among its declarations, the letter featured a direct plea to AI developers to focus on "safeguarding humanity."

"I wish to address a special appeal to those who develop artificial intelligence," Leo writes. "In one sense, technological innovation can represent human participation in the divine act of creation. Developers, therefore, bear a particular ethical and spiritual responsibility, for every design choice reflects a vision of humanity."

And this wasn't a rhetorical appeal by the pope. Leo was joined in the Vatican by Anthropic co-founder Chris Olah, whose multi-hundred-billion-dollar San Francisco-based AI company is responsible for developing the large language model, Claude.

Theologians and clergy also greeted the pope, who presented them with "Magnifica humanitas" at around 11:30 a.m. local time on Monday.