The fifth precept, in Pali, reads
Suramerayamajja pamadatthana veramani sikkhapadam samadiyami
I do not know Pali, but from what I understand, this is literally interpreted as a prohibition against alcohol only. (Avoiding fermented drinks that cause heedlessness).
There are several levels of interpretation that I could see here:
- The most literal would be to intepret the precept as being against alcohol only. This level is fermented drink + intoxicant + heedlessness.
- The next level might be to intrepret it as prohibiting any substance which could cause heedlessness - although what counts as "heedless" might be open for debate. Does marijuana cause heedlessness, for example?* This level is intoxicant + heedlessness.
- The next level would be against any type of substance that causes "intoxication" more broadly speaking. You might argue that marijuana does not cause heedlessness, for example, but it is certainly an intoxicant. Any type of drug which the government forbids you to operate heavy machinery on while under the influence would be an intoxicant. This level is intoxicant alone.
- The next level would be against any substance which causes a shift in mental state. This would include things like caffeine, but it looks like most monks allow themselves to drink tea. (Tea also contains L-theanine). Mild over the counter sleep supplements would also count. (It should be noted that nicotine, viewed as a substance alone, seems to be more in category 4 than any other category). This level is a step below “intoxicant,” but still mind altering.
There are other wrinkles as well. What about drugs prescribed by doctors with side effects? Or antidepressants? Psychedelic assisted therapy?
My question here is if there is a consensus as to the correct level of interperation among academic/monks currently practicing.
*I would say yes it does cause “heedlessness”. But the point here is not to debate this; the point is that there might reasonably exist a class of drugs which are intoxicating but do not cause heedlessness.