...Thomas is transgender, which rules him out of consideration for the priesthood. He works for a Catholic employer who does not know his gender identity, so to protect his job, he asked to be identified in this story only as Thomas, the name he chose when he completed the Catholic rite of confirmation, which all Catholics take to mark their commitment to the faith as adults.

Transgender Catholics like Thomas say they feel they are in doctrinal limbo since, although there is extensive teaching on sexuality that applies to lesbian and gay Catholics, there is no universal church teaching on transgender identity. They want to be recognized with clearer, more authoritative guidelines from the pope on issues like medical transition, vocation, and marriage.

...But in conversation, Francis has also appeared to reject the idea that gender can be different from the sex assigned at birth. He has repeatedly said that gender is not a choice. “Children are learning that they can choose their own sex. Why is sex, being a woman or a man, a choice and not a fact of nature?” he said in a 2017 interview. He has also railed against “the biological and psychological manipulation of sexual difference” that presents gender as a “simple matter of personal choice.”

Several US bishops appeared to echo the pope’s views on gender in December 2017. In an open letter called “Created Male and Female,” they wrote, “The socio-cultural reality of gender cannot be separated from one’s sex as male or female. ... The movement today to enforce the false idea — that a man can be or become a woman or vice versa — is deeply troubling.” The letter does not constitute a universal church teaching, since church teaching has different levels of authority.