The Diocese Report Has Posted the 1961 Vatican Document that spells out who cannot be admitted to the novitate. Now that I read through the document, I recall having read it before in Jerusalem in 1979 in a religious bookstore there. It was never used as a guide in the seminary that I taught at, in fact if it had we would have had to close down for lack of suitable candidates (which probably is a testimony of how bad things are). It forbids allowing:
1. Those who are weak willed or obsessed with sex. Think here the guy who preaches about it all the time or the guy who looks like he can's say "no" to a good meal even when the doctor tells him that its killing him.
A candidate who shows himself certainly unable to observe religious and priestly chastity, either because of frequent sins against chastity or because of a sexual bent of mind or excessive weakness of will, is not to be admitted to the minor seminary and, much less, to the novitiate or to profession. If he has already been accepted but is not yet perpetually professed, then he should be sent away immediately or advised to withdraw, according to individual cases, no matter what point in his formation he has already reached.
2. Those who have problems with solitary acts (masturbation). It is amazing how vague they are when they write these things (maybe they lose something in the translation.
Consequently, any candidate who has a habit of solitary sins and who has not given well-founded hope that he can break this habit within a period of time to be determined prudently, is not to be admitted to the novitiate. Nor can a candidate be admitted to first profession or to renewal of vows unless he has really amended his ways.
3.Those who sin with someone of the same-sex (homosexual acts). Unless they are seduced and penitent.
If a student in a minor seminary has sinned gravely against the sixth commandment with a person of the same or the other sex, or has been the occasion of grave scandal in the matter of chastity, he is to be dismissed immediately as stipulated in canon 1371, except if prudent consideration of the act and of the situation of the student by the superiors or confessors should counsel a different policy in an individual case, sc., in the case of a boy who has been seduced and who is gifted with excellent qualities and is truly penitent, or when the sin was an objectively imperfect act.
Advancement to religious vows and ordination should be barred to those who are afflicted with evil tenencies to homosexuality or pederasty, since for them the common life and the priestly ministry would constitute serious dangers.
4. Those of a "sensitive" nature.
Very special investigation is needed for those students who, although they have hitherto been free of formal sins against chastity, nevertheless suffer from morbid or abnormal sexuality, especially sexual hyperesthesia or an erotic bent of nature, to whom religious celibacy would be a continual act of heroism and a tryring martyrdom. For chastity, in so far as it implies abstinence from sexual pleasure, not only becomes very difficult for many people but the very state of celibaby and the consequent loneliness and separation from one’s family becomes so difficulty for certain individuals gifted with excessive sensitivity and tenderness, that they are not fit subjects for the religious life.
5. Then for the rest:
In addition, special attention must be paid to those who give evidence of neuropsychosis and who are described by psychiatrists as neurotics or psychopaths, especially those who are scrupulous, abulic, hysterical, or who suffer from some form of mental disease (schizophrenia, paranoia, etc.). The same is true of those who have a delicate constitiution or, particularly, those who suffer from weakness fo the nervouse syastem or from protracted psychic melancholia, anxiety or epilepsy (can. 984, 3) or who are afflicted whith obsessions. Similarly, precautions are needed in examinining the children of alcoholics or those tainted with some hereditary weakness, especially in the mental order (cf. Stat. Gen., art 33; 34, :1). Finally, those young men are in need of special attention who manifest exaggerated attachment to the comforts of life and worldly pleasures. Superiors should carefully examine all these types and subject them to thorough examination by a prudent and expert Catholic psychiatrist who, after repeated examination, will be in a position to determine whether or not they will be able to shoulder, with honor to that state, the burden of religious and priestly life, especially celibacy.
Lest this be seen as an attack on "just" homosexual candidates, I think a careful reading would exclude just about every candidate I've ever known which is probably why it never was enforced. Even for some very "celibate" priests, the last one which deals with the "comforts of life" and "worldly pleasures" would have gotten them--think of the priest with the big expensive car and the fine art collection.