That gives me a chance to review the commentarial literature on this. Note that I am not very familiar with this literature, and must rely on the search at tipitaka.org.
In an earlier draft of this note, I made some mistakes, especially by saying the fivefold classification of pandakas was not found in the commentaries. It is, and I have corrected the following to account for this.
Let’s start with a look at the commentaries by Buddhaghosa. While they are not canonical or authoritative in the same sense as the Vinaya itself, they are very influential in Theravada countries. While the editor and compiler of the commentaries is Buddhaghosa, for the most part they record the ideas and opinions found in the older commentaries on which they are based.
This seems to be the primary source of the most important passage on the pandaka, the fivefold categorization. Here I’m just going to translate the main passage as literally as I can, and summarize any other relevant material, without interpretation.
Paṇḍakobhikkhaveti ettha āsittapaṇḍako usūyapaṇḍako opakkamikapaṇḍako pakkhapaṇḍako napuṃsakapaṇḍakoti pañca paṇḍakā.
“Monk pandaka” means: In this context there are five pandakas: the “sprinkled pandaka”, the “jealous pandaka”, the “castrated pandaka”, the “periodical pandaka”, the “genderless pandaka”.
Tattha yassa paresaṃ aṅgajātaṃ mukhena gahetvā asucinā āsittassa pariḷāho vūpasammati, ayaṃ āsittapaṇḍako.
Therein, one whose passion is satiated by being sprinkled with semen after having taken the genitals of another in the mouth is a “sprinkled pandaka”.
Yassa paresaṃ ajjhācāraṃ passato usūyāya uppannāya pariḷāho vūpasammati, ayaṃ usūyapaṇḍako.
One whose passion is satiated by the arising of jealousy when seeing the transgression of others is a “jealous pandaka”. (Note: I translate according to the normal meaning of usūya, but here obviously “voyeur” is more idiomatic. )
Ekacco pana akusalavipākānubhāvena kāḷapakkhe paṇḍako hoti, juṇhapakkhe panassa pariḷāho vūpasammati, ayaṃ pakkhapaṇḍako.
And someone who due to the power of the ripening of unwholesome kamma is a pandaka on the waning lunar cycle, but whose passion is satiated in the waxing cycle should be known as a periodical pandaka.
Yassa upakkamena bījāni apanītāni, ayaṃ opakkamikapaṇḍako.
One whose testicles have been surgically removed is a castrated pandaka.
Yo pana paṭisandhiyaṃyeva abhāvako uppanno, ayaṃ napuṃsakapaṇḍakoti.
And one who at the time of rebirth manifested no gender is a “genderless pandaka”.
Tesu āsittapaṇḍakassa ca usūyapaṇḍakassa ca pabbajjā na vāritā, itaresaṃ tiṇṇaṃ vāritā.
Of these, the sprinkled pandaka and the jealous pandaka are not prevented from going forth, while the remaining three are.
Tesupi pakkhapaṇḍakassa yasmiṃ pakkhe paṇḍako hoti, tasmiṃyevassa pakkhe pabbajjā vāritāti kurundiyaṃ vuttaṃ.
It is said in the Kurundi commentary that the periodical pandaka is only prevented from going forth on the half of the lunar cycle when they are pandakas.
Yassa cettha pabbajjā vāritā, taṃ sandhāya idaṃ vuttaṃ – ‘‘anupasampanno na upasampādetabbo upasampanno nāsetabbo’’ti.
This was said (in the canonical passage on which this is commenting) in reference to those in this context whose going forth is prevented: “If they have no taken ordination they should not be ordained, and if they have ordained they should be expelled."
Note that the term I’m translating as “passion” here is pariḷaha, literally “fever”, which is an unusually strong term for lust, but one that is regularly used in this context.
Returning to the Mahākhandhakaṃ, there is one more passage of note:
Paṇḍakāti ussannakilesā avūpasantapariḷāhā napuṃsakā; te pariḷāhavegābhibhūtā yena kenaci saddhiṃ mittabhāvaṃ patthenti
“Pandaka” means: full of defilement, with unsated passion, genderless. They’re completely overwhelmed with passion no matter with whom they wish to befriend.
I’m not entirely sure what the “friend” thing here is about.
The description of the pandaka as “full of defilement, with unsated passion, genderless” occurs in a few other commentaries.
Mentions pandakas a number of times, but with little of substance. It mentions the idea of a “female pandaka”:
Itthipaṇḍakāti animittāva vuccati
“Female pandaka” means: they’re said to be completely without gentialia.
In a discussion of those whose kamma is an obstruction, the pandaka is mentioned as one whose rebirth kamma is an obstacle due to the result of past kamma.
Subcommentaries
The five-fold categorization of pandakas clearly became the standard passage on the topic. It appears in four Vinaya subcommentaries (ṭīkā) and another text categorized as “other”. All of these must post-date Buddhaghosa’s work in the 5th century, but I can’t date them any more precisely than that. There are minor differences, but they are pretty similar.
A further explanation for the periodical pandaka is added in the Sīmavisodhanīpāṭha, that one may be a woman for the waning fortnight, a man for the waxing fortnight.
Regarding the periodical pandaka, the Sīmavisodhanīpāṭha notes a difference of opinion. If they ordain while not a pandaka, some say they must be expelled when they transform into pandakas; while others say that if they succeed in ending the defilements they may remain in robes.
In addition to the sources quoted above, this is the only other relevant passage in the late literature on the pandaka I can find. This doesn’t have the same passage, but rather paraphrases it to the same effect, in the context of who is allowed to take full ordination.
Tesu āsittapaṇḍakañca usūyapaṇḍakañca ṭhapetvā opakkamikapaṇḍako napuṃsakapaṇḍako paṇḍakabhāvapakkhe ṭhito pakkhapaṇḍako ca idha adhippeto.
Of these, leaving aside the sprinkled pandaka and the jealous pandaka, what is referred to here is the castrated pandaka, the genderless pandaka, and the periodical pandaka so long as the period lasts.
Conclusions
So this little inquiry reveals a number of interesting details. Since these passage all occur in late literature, none of them are normative. They represent the opinions of certain teachers, no more.
- Only two kinds of pandaka are absolutely prohibited from ordaining: the castrate and the one born genderless.
- The sprinkled and the voyeur refer to behaviors, to habits, “vices” or “fetishes” if you will, rather than biological characteristics. Thus it makes sense that if they can change their behaviors they can ordain.
- The periodical pandaka is clearly mythological.
- As to the genderless one, the definition is quite explicit here. It would not include someone who had unusual gender characteristics, but only someone genuinely devoid of any genitals.
- The castrated one refers to the removal of “seeds”, so this would not include a woman who had suffered female genital mutilation.
Further to these clear conclusions, let me make a few more interpretive reflections.
The definitions of the “sprinkled” and the “voyeur” are, of course, a little weird. But I think it would be reasonable to take these as referring to sexual fetishists in general.
The problem here is that the core sexual act discussed in the Vinaya centers on “normal” penetrative sex; other sexual acts don’t require expulsion. But for some fetishists, penetration is irrelevant or at least not central. So if someone enjoyed being strapped up and whipped, they could probably get away with it according to Vinaya.
We could take this as a precedent to cover such cases. If someone does enjoy some form of non-penetrative fetish, they need to give it up before ordination.
The definition of the castrate does not address the question of whether they have been castrated by their own choice, or by some outside force. The relevant term upakkamati is used in both senses.
It seems, however, that part of the idea of the pandaka is that such a state is a product of bad kamma; or at least, this is explicitly stated in the case of the periodical pandaka.
If this was taken to apply also to the castrate, it would mean the term only applied to those who have chosen to castrate themselves. Acts of violence by others, or medical conditions, have no necessary connection with past kamma.
It is not unheard of in ancient religions for men to deliberately castrate themselves as a spiritual deed, and indeed such a case is recorded in the Vinaya, and condemned by the Buddha: “You left what should have been cut off, and cut off what should have been left!”
Someone who was castrated for medical reasons, or through violence, would not count. So anyway, I don’t think the text is definitive, but it would not be unreasonable to restrict this to cases of deliberate self-castration.