In the US, the now-(thankfully)-retired Justice Kennedy laid it out in his infamous Lawrence v Texas blather; going forward, the Official Narrative would be that which was first mouthed by Simone de Beauvoir: “one is not born a woman, one becomes so”
Later on, the Jesuits would adopt the position that "individual experience" is the defining guide to reality (GC 31, 1965), which is de Beauvoir's maxim writ large, and thus Kennedy, and all that follows, including gay "marriage" and "transvestite" rights.
Buried in the rubble of the avalanche triggered by de Beauvoir, Kennedy, and Martin is reality.
...The mere idea of heterosexual “orientation,” as one of two species of the genus sexuality, is already “gay,” since both “species” presuppose that sexual desire and identity are only arbitrarily related to a meaningless biological substrate. This same dualistic understanding is the premise of the revolution in assisted reproductive technologies and the normalization of surrogacy. Transgenderism follows quite logically from this premise, just as surely as the push for transgender rights followed the Obergefell decision in time. Yet if “gender,” like “orientation,” is merely a function of a self-appropriated identity distinct from one’s sexually differentiated body (now relegated to the realm of “mere biology”), then in fact there is no longer any such thing as man or woman as heretofore understood. We are all transgender now, even if gender and sexual identity accidentally coincide in the great majority of instances....
(This is why the term "gender" has replaced "sex." Language governs thought process; obscuring 'what IS' by pasting it over with 'what might, or could, or wanna be' facilitates the lie.)
Somehow, this twisted-think rose to higher levels in the Church and now appears to have fully engulfed Rome. That's surprising, given that both John Paul II and Benedict XVI saw it for what it was and wrote extensively against it. Here's Benedict on the matter:
The Chief Rabbi of France, Gilles Bernheim, has shown in a very detailed and profoundly moving study that the attack we are currently experiencing on the true structure of the family, made up of father, mother, and child, goes much deeper. While up to now we regarded a false understanding of the nature of human freedom as one cause of the crisis of the family, it is now becoming clear that the very notion of being—of what being human really means—is being called into question. He quotes the famous saying of Simone de Beauvoir: “one is not born a woman, one becomes so” (on ne naît pas femme, on le devient). These words lay the foundation for what is put forward today under the term “gender” as a new philosophy of sexuality. According to this philosophy, sex is no longer a given element of nature, that man has to accept and personally make sense of; it is a social role that we choose for ourselves, while in the past it was chosen for us by society. The profound falsehood of this theory and of the anthropological revolution contained within it is obvious. People dispute the idea that they have a nature, given by their bodily identity, that serves as a defining element of the human being. They deny their nature and decide that it is not something previously given to them, but that they make it for themselves. According to the biblical creation account, being created by God as male and female pertains to the essence of the human creature. This duality is an essential aspect of what being human is all about, as ordained by God. This very duality as something previously given is what is now disputed....So the 'new Church', guided by Pp. Francis' coterie, has bought the lie of de Beauvoir and issues orders to "accompany" people afflicted with perversion (for that IS the correct term) rather than to voice, persuasively, the Old and Unchanged Truth: ".......male and female He created them." It's not fashionable.
Far more, and much better voiced, is available at First Things. Read it. Pp. Francis won't.