October 16

Regarding ...'s question about the areas of the Guardian's infallibility, we note that the letters written on his behalf on the subject of homosexuality represent his interpretation of the revealed Word on the subject, and are authoritative. They do not, for example, stray into the realm of science, a field in which, as the Guardian himself points out, he is not infallible, by speculating on the possible biological or psychological cause of a predisposition to homosexual tendencies. They do reflect the Guardian's interpretation based on an infallible understanding of the entire Revelation of Bahá'u'lláh, and form a coherent and consistent whole with the entire body of Bahá'í Sacred Literature and authoritative texts. 
(Memorandum from the Research Department of the Universal House of Justice, dated May 3, 1994)