One other thing to note is that the original Vinaya regulations were neither precepts nor vows, but rules. They might be considered kind of house rules specifically aimed at a male community younger in age.
With these facts in mind we can then examine the original reason for the alcohol prohibition. For this purpose we can examine the various Vinaya texts that exist in translation in the Chinese canon. These were all translated in the 5th century. Preference in this context might be given to the Mahāsāṃghika Vinaya as it is probably the earliest and most reliable version. Incidentally, the issue of expanding the Vinaya was an issue that contributed to the first schism in the early sangha. See the following.
“The Mahāsāṃghikas were involved in the first division of the Buddhist community in the second century after the demise of the Buddha, that is, the schism between the Mahāsāṃghikas and the Sthaviravādins. This schism was most likely invoked by the expansion of the root Vinaya text by the future Sthaviravādins, an expansion that was not accepted by the later Mahāsāṃghikas.”1
We can thus assume that the Mahāsāṃghika Vinaya 摩訶僧祇律 is the earlier version and likely better reflects the original narrative concerning the incident which led to the Buddha prohibiting alcohol consumption. We might consider the Mahāsāṃghika account in its entirety as follows.
《摩訶僧祇律》卷20：「佛住拘睒彌國。廣說如上。爾時拘睒彌界有惡龍。名菴婆羅。能使亢旱不雨苗稼不收。人民飢饉。如是種種災患。時尊者善來比丘往降惡龍。如善來比丘經中廣說降伏惡龍已。乃至國土豐樂人民感德。知恩報恩。有五百大家為善來故。各立常施幢幡施設床座。請僧供養。別請善來比丘。其所造家。則設種種美食。時有一家施食之後。因渴施酒色味似水得而飲之。還向精舍。爾時世尊大會說法。酒勢發盛。昏悶躃地。當世尊前舒脚而臥。佛知而故言。是何比丘在如來前舒脚而臥。比丘答言。善來比丘飲酒過多是故醉臥。佛問諸比丘。此善來比丘先曾晝寢不。不也世尊。復問比丘善來。未醉之時頗曾佛前舒脚臥不。不也世尊。復問比丘多飲酒已。欲使不醉可得爾不。不也世尊。復問諸比丘。設使善來比丘不飲酒時聞說微妙不死之法。當欲失是善利。不聽受不。不也世尊。佛語諸比丘。是善來比丘本能降伏惡龍。今者能降蝦蟆不。答言。不能。佛言。設使菴婆羅龍聞者生其不樂。從今日後不聽飲酒。」(CBETA, T22, no. 1425, p. 386, c13-p. 387, a4)
The Buddha was residing in the country of Kauśāmbī teaching as was mentioned above. At that time in the realm of Kauśāmbī there was an evil nāga named Āmra who had caused a drought where the rain did not fall and the crops were not harvested. The people were starving and there were various calamities like this. It was then that the bhikṣu Venerable Svāgata went to placate the evil nāga. As it is explained in the *Svāgata Bhikṣu Sūtra, after placating the evil nāga the country celebrated and the people felt gratitude, aware of the kindness bestowed upon them and wanting to repay it. It was on Svāgata's behalf that five hundred great families each offered up hanging banners and setup seats, inviting the monks for offerings. They made a special invitation to Bhikṣu Svāgata. The households which made [the offerings] provided various kinds of delicious foods. It was then that after one household had offered food that due to his thirst they offered alcohol which appeared as water whereupon he drank it. He returned to the monastery where the World Honored One [the Buddha] was teaching the Dharma in a great assembly at the time. The influence of the alcohol was all too much as he became unwell and fell onto the ground. It was in front of the World Honored One that he stretched out his legs and passed out.
The Buddha was aware of this and thus said, “Which bhikṣu is it here that has stretched out his legs and passed out in front of the Tathāgata?”
The bhikṣus replied, “Bhikṣu Svāgata drank much alcohol and thus has become inebriated and passed out.”
The Buddha asked the bhikṣus, “Has Bhikṣu Svāgata here ever slept during the day?”
“No, World Honored One.”
He again asked, “Has Bhikṣu Svāgata prior to being inebriated ever stretched out his legs and passed out in front of the Buddha before?”
“No, World Honored One.”
He again asked, “The bhikṣu having drank too much alcohol, if he wanted to make himself un-inebriated, would it be possible to do this?”
“No, World Honored One.”
He again asked the bhikṣus, “Suppose Bhikṣu Svāgata at a time when he had not drank alcohol heard an exposition on the excellent and immortal Dharma – would he want to lose this benefit and not listen to it?”
“No, World Honored One.”
The Buddha said to the bhikṣus, “This Bhikṣu Svāgata was originally able to placate an evil nāga. Now, could he placate a toad?”
They replied, “He could not.”
The Buddha said, “Suppose Āmra the nāga heard this – it would provoke his displeasure. From today onward it is not permitted to drink alcohol.”
Curiously, the accounts of this incident in other Vinaya texts differ in the details of what transpired.
The Dharmagupta Vinaya 四分律 is a much longer account of the event and the substance consumed is a “black liquor” which the monks were aware was alcohol. It also states Svāgata not only fell over at the road side, but vomited which caused the birds to be disturbed. The Buddha then tells Ānanda the ten faults of consuming alcohol.
The Mahīśāsaka Vinaya 五分律 reports the nāga was causing torrential rains and hail which destroyed the fields, in contrast to the account in the Mahāsāṃghika Vinaya which states it was a drought. Svāgata is also seen in a non-violent battle of magical powers with the nāga where the latter loses and is scooped up into the former's bowl and taken to the Buddha who gives him permission to release it. The grateful laity come to the assembly of monks and ask Svāgata if he needs anything. He replies that when he was layperson he enjoyed meat and alcohol. The laity then provided him with both meat and alcohol which resulted in him becoming drunk, vomiting all over robe and bowl, and passing out. The Buddha saw this with his clairvoyant eye from afar and went with Ānanda to tend to Svāgata and clean him up with water from the well. They placed him on a rope-bed and in a drunken haze Svāgata kicked the Buddha. It was then that the Buddha summoned the assembly of monks and spoke to them of the faults of alcohol. He then prohibited the consumption of it.
In consideration of all these differing details of the incident we can understand two things.
Firstly, all the accounts agree that Svāgata became intoxicated due to having consumed too much alcohol following festivities celebrating his placation of an evil nāga that was terrorizing the people of Kauśāmbī, which we can assume more or less reflects the actual event that took place, or at least the general hearsay concerning it, albeit with differing accounts of the details.
Secondly, the differences we find in the various Vinaya collections tell us that when it comes to knowing precisely what was said and done when the Buddha lived we are actually at a loss to safely conclude anything as matter of fact. There is a general tendency in modern Buddhist scholarship to chiefly favor the Theravāda Pāli canon as representing what the “historical Buddha” actually taught and the events of his life. However, this is problematic for the simple fact that the canons from other early Buddhist schools such as that of the Mahāsāṃghikas, who incidentally are noted as having disagreed to the expansion of the Vinaya unlike the Sthaviravāda (Theravāda) school, have differing accounts of the Buddha's teachings and the events which occurred in the early community. As noted above, in the case of the alcohol prohibition there is indeed agreement on the general outline of the incident, but the details differ. This is likewise to be expected when it comes to teachings as recorded in the various differing editions of sūtras that we have, many of which are preserved in Classical Chinese which exasperates the problem.
What this means is that essentially we only have the general outline of the Buddha's teachings and the events of his life available to us, thus we must accept this limitation rather than believing any particular scriptural record to be a verbatim record. This is important in the process of exegesis where we must not place too much faith on the fine points of scriptures which record the Buddha's words as said records are in reality quite limited as records and we have really only to rely on their general meanings. In other words, we need to rely on the spirit and general outline of many teachings rather than the letter of how it is recorded as having been presented.
Returning to the issue of alcohol prohibition, it goes without saying that Buddhism developed in most cultures to generally see alcohol in a negative light, although we need to remind ourselves that in the early sangha alcohol was not prohibited and Buddhists could and evidently did consume it. There are also a lot of secondary literature such as treatises which discuss the issue in an ethical context as well as in a practical context of how it might affect one's cultivation of mindfulness. It was thus absolutely forbidden. This prohibition also came to be included among the five lay precepts, which is a characteristic set of vows that Buddhist laypeople are generally expected to undertake.
Many Mahāyāna thinkers reacted against rigid interpretations of rules and precepts arguing that if motivated by compassion or other benevolent purposes, then committing acts that would otherwise be outright violations of one's precepts would actually be meritorious. This perhaps lead to a relaxed attitude towards alcohol consumption both in China and Japan, and elsewhere. There is an expression still favored in Japanese Buddhism to this day to refer to liquor as “prajñā soup” 般若湯, which actually originates in Song Dynasty (960–1279) China. The reasoning seems to have been that by calling it something else then, in good humor, it was not alcohol and thus did not violate any precepts.
In summary, we have reviewed the original reason for the Buddha prohibiting alcohol and we can indeed see it was not due to the beverage being inherently unwholesome and evil, but the regulation was actually a practical rule established with the disciples in mind and likely with a wish that no repeat of the incident would occur. In that sense, there is nothing holy or sacred about such a rule. This is also an important thing to note: the Vinaya regulations were rules in the beginning rather than vows. The earliest disciples were also free to consume alcohol and they did. The differing accounts of these regulations also leads us to the perhaps unfavorable conclusion that we really cannot faithfully rely on any single account for the fine details of what the Buddha said and the circumstances in which he taught things due to the various records we have differing to the extent that they do. In other words, we have the general outline of his wording and the events which prompted his declarations and statements, but no verbatim text from which fine exegesis based on the letter of the teaching might be executed.
1See Bart Dessein in "The First Turning of the Wheel of the Doctrine: Sar and Maha Controversy" in Handbook of Oriental Studies The Spread of Buddhism, edited by Ann Heirman and Stephan Peter Bumbacher (Leiden: Brill, 2007), 15.