As humans we should use all plants
Wait, what? We should use lethal plants?
its not like I said we should all start to randomly munch away in a garden of poisonous mushrooms. However even that which may be poisonous for direct digestion can contain things that if limited to a specific small dose by professionals can be good and even life saving.
Eating cannabis does not get you high and is one of the most effective medicines on the planet. Marijuana has been used by mankind and has been common in human society for thousands of years and just exande we happen to live in a moralistic anglophile civilization that forbids anything that does not comply to its cultural boundaries doesnt mean that it's either sound or right considering that in the broad sweep of history this civilization in it's current form is only a couple of hundreds of years (and is declining now) and is an anomaly.
Personally I dont think any governmental body has any right what so ever to tell a sovereign human being what out of the fruits of the earth is permissable to use, as long as it does not kill anyone else. To think that a government has the right to forbid us to eat/smoke a naturally occuring plant because it's narrow cultural frame of reference find the behaviour overdosage might produce in certain individuals "in-decent" seems to me as borderline idolatrous and an affront to the creator. Consider that alcohol is rated the 2nd most dangerous drug in the world after injecting heroin and one realises that this is really not a problem with the substance itself but a cultural problem.
To move towards legalisation in the western world is well on its way and is the only sane option since governments really have no bussiness walking around earth as a benevolent creator telling the soil which plants not to bring up and telling creatures what natural plants not to digest.
The reason I believe this so strongly is that marijuana needs no chemical processing to be used while alcohol needs a rather complex process to be produced.
I would consult what church fathers and saints have said about this in the past or about alcohol as a comparison.
Rember also that in roman civilization (at least early one) drugs were very common among all classes of society and marijuana would probably be viewed more as a medicine 1st, recreational drug 2nd in these cultures. I know Opium was and its a far more powerful drug than marijuana as it constitutes the basic substance from which morphine and heroin was later produced through chemical manipulation and refinement. But most of these plants are alot less potent in their natural form and that is the only way I think we should use them for any recreational purposes (if you cant avoid recreational drug-use that is). Most people se recreational drugs in their lives but in the west this has been limited as much as possible to alcohol. But some people can never feel comfortable with alcohol as its effects in direct correlation with the dosage seem to be only a lack of balance and a significant increase of general stupidity. Marijuana however, while relaxing slightly opens up the mind to a deeper side of the human self and is very unlikely to result in violent behaviour of any sort. This has always been the go-to drug for certain kind of people in society and making this illegal has only bad consequences. When a 16-year old want to smoke weed in most of todays western societies it is necessary for him to come into contact with criminals as the plant is outlawed. As well as stigmatizing the 16-year Old in the eyes of general society by alienation from generally accepted culturural behaviour (increase in LACK of belonging) it drastically increases the possibility of personalities who in normal circumstances might have never considered a criminal lifestyle to now identify with criminal culture as it may seem more accepting of his life than general law-abiding culture. It also puts people not naturally prone to criminal behaviour or harder drugs to later on (if the habit continues) inevitably be offered to buy heroin, amphetamine, cocaine or other harder drugs and since marijuana is an illegal drug the reasoning might have one consider much harder drugs and eventually result in addiction because for the general society there's not much difference between certain illegal drugs esp. in the eyes of the law while in reality the potency difference between cannabis and cocaine is line between sugar and a bottle of vodka.
It also makes many young people lose trust in the states ability to know what is best for their life when they discover that the effect of alcohol is much more severe & potent than that of marijuana while the latter is illegal