So I thought it was homosexuality on my first read, which this article argues for. The phoenix as male-begetting-male and the evidence of
El rito constituye el Secreto. Este, como ya indiqué, se trasmite de generación en generación, pero el uso no quiere que las madres lo enseñen a los hijos, ni tampoco los sacerdotes; la iniciación en el misterio es tarea de los individuos más bajos. Un esclavo, un leproso o un pordiosero hacen de mistagogos. También un niño puede adoctrinar a otro niño.seem to support the idea well enough, but the one thing that sticks out in my mind against the theory is the passage "the sectarians are indistinguishable from the rest of the world: the proof of it is that they have not suffered persecutions". But this story was written in 1952! Wasn't that long enough after WWII that evidence Hitler's persecution of homosexuals had already appeared?
[The rite itself constitutes the Secret. And the Secret, as I have already indicated, is transmitted from generation to generation; but usage does not favor mothers teaching it to their sons, nor is it transmitted by priests. Initiation into the mystery is the task of individuals of the lowest order. A slave, a leper, a beggar plays the role of mystagogue. A child can indoctrinate another child]
Anyway, I also read some stuff here about how Terrence McKenna seems to think it's about DMT trips, but that seems like a stretch. I could almost believe opium use.