During the ordination ceremony, the priest’s hands are anointed with oil, he lies prostrate on the ground to symbolize the laying down of his life, and the bishop’s hands are laid on his head. Like baptism and confirmation, ordination leaves an “indelible mark” on the priest’s soul.

During his priesthood, the priest uses his mouth to preach and to speak the words of blessing and consecration, his hands to elevate and distribute the Eucharist, and his heart, mind and soul to pray.

In an interview with Vox, Franciscan Sister Ilia Delio, who holds the Josephine C. Connelly Endowed Chair of Theology at Villanova University, said that Catholicism should “reimagine” the priesthood and consider robots instead of, or alongside, men.

“The Catholic notion would say the priest is ontologically changed upon ordination. Is that really true?” Delio told Vox. “We have these fixed philosophical ideas and AI challenges those ideas – it challenges Catholicism to move toward a post-human priesthood.”

Delio said robotic priests would have certain advantages – including being incapable of committing sexual abuse.

But numerous Catholic experts told CNA that a robot priest would be sacramentally impossible in the Catholic Church, explicitly because they are not humans.

Sister Mary Christa Nutt, RSM, told CNA that robots cannot be priests because they are incapable of having an intellect or a will with which to cooperate with God’s grace.

“It has to do with our Catholic understanding of the need for human mediation, cooperation with interior grace,” Nutt told CNA.

“We’re not dualists,” she said. “So we don’t separate the importance of the rites, and the bodily involvement of all the senses in the rites are very important. But they don’t of themselves suffice. There has to be the interior cooperation of intellect and will.”

Robots are programmed, she said, and are incapable of having a will and an intellect or an interior prayer life of their own. A human soul, conformed to Christ, and belonging to someone willing to participate in the sacraments, is what makes the grace of those sacraments efficacious, she said.

“We believe that the priest is in the person of Christ, so only a human being can participate in the person of Christ with intellect and will,” Nutt said.

“How would a robot cooperate by intellect and will interiorly with grace to be conformed to Christ ontologically? It just makes absolutely no sense. It’s so outside the realm of possibility when you have a sacramental logic and you have absolutely no dualism in the religion,” she said.

Fr. John Kartje is the rector of Mundelein Seminary in Illinois. Kartje told CNA that his background in physics meant that he found the story about the possibility of robot priests intriguing.

He said that according to the article, Buddhist priests might be possible, because they are people simply guiding people along a path. But for Catholics, he said, their faith necessitates an encounter with a person – God.

“For Christians, prayer or any sort of religious activity is not primarily a path, but it’s an encounter with a person…with God. And so, that for me is the fundamental distinction. What the priest is doing, he’s acting in persona Christi, in the person of Christ,” Kartje said.

“He’s also helping to facilitate in a sacramental way making really present that encounter between the Catholic and the divine, but not just the divine as some sort of vague concept, but with the real person of God, that real person of Jesus Christ.”

Kartje added that that does not mean that Catholics should fear technological advancements or even artificial intelligence, because these can be helpful, even in the context of faith.

“I mean, in some degree, we all make use of simple artificial intelligence without thinking about it in the same way. Our phones are based on algorithms, which make decisions without our directly being involved with them,” he said. “Most priests have breviaries on their phones, which program ahead and let us pull up the (daily Mass) readings.”

Sister Nutt also said that technology can be a helpful tool in learning the faith. In the Vox article, author Sigal Samuel mentions the SanTO robots, developed by a Japanese roboticist, which resemble saint figurines and can recite certain prayers if prompted.

Such robots, Nutt said, could help children memorize prayers, but “the prayer has no significance outside of its material reality, unless it’s said by a human being who offers it to God interiorly.”

When we are faced with advanced technologies, Fr. Kartje said, we should allow the questions that they bring about to help us hone our understanding and definitions of human beings and free will.

Still, he said, a robot could never replace a person, because it cannot encounter God or act on its own free will.

“A robot is the encounter of an algorithm with the natural world, and a human is the encounter of the divine with the natural world,” he said.

Dr. Kevin Miller, an associate professor of theology at Franciscan University of Steubenville, told CNA that in order to understand the priesthood, Catholics must look to Jesus Christ. And Jesus is, decidedly, not a robot.

“The sacraments are instituted by Christ and configure us to Christ in various ways. In Christ, God the Son took on a human nature ‘for us men (human beings) and for our salvation,’” he said, quoting the Nicene Creed.

“The sacraments are part of the same saving plan. The sacraments are for human beings, in the sense that they can be neither received nor administered by robots or AI devices or the like (or any other non-human created beings),” he said.

“All of this is, pace Sister Ilia Delio, ‘really true,’ and cannot be ‘reimagined.’”