Most narcotics are detrimental to one's health in several ways, so there is some warrant for their illegality aside from the subcultures that use them.
But classic psychedelics and cannabis do not pose significant health risks, so I know that their illegality is bound to a WAR ON CULTURE:
The REAL REASONS PSYCHEDELICS/CANNABIS BECAME ILLEGAL are largely social, political, and behavioral. Let's face it: long term use of them DOES change people, more or less obviously. And the WAYS IN WHICH they change people make them a threat to the people in power and a threat to the institutions/values for which they stand.
For example, psyches/cannabis (to varying extents) promote:
1) Community values (sociability with others, sharing, bartering),
2) Creativity,
3) Dialogue on existentialism (Does science really explain everything? What if this is reality... what if this is our origin...)
4) The rejection of materialism (I can live without all these fancy possessions, happiness is not dependent on objects)
5) Introspection (why live this way? why do this/that? How can I be truly happy? What is morally correct? How do we improve the state of the world?),
6) The dissolution of social/ego boundaries ("me vs. you", "us vs. them" fades away).
As Terence Mckenna once said, "the tension between 'straight' culture and 'psychedelic culture' is a tension between values." This statement is right on, because I guarantee you that if the above values were to prevail, it would be the socioeconomic elites' worst nightmare. To show this, now let's look at the values that keep the elite in power:
1) Capitalism ( greed, financially motivated, what is mine is mine)
2) One-track thinking (thinking "inside the box", thinking 'normally')
3) Self-repression (your voice does not matter, the powerful will make decisions)
4) Determinism (Science explains everything, what you cannot perceive cannot be real, our view of human origin is the correct opinion)
5) Crass materialism (you worth IS measured by your material possessions, you will be respected if wealthy, and ridiculed if poor)
6) Conformity (Do not think for youself, follow the pre-established view about what is the right way to live, follow the majority, do not ask questions!)
7) Reinforcement of Social/Ego boundaries ((define yourself, compete with your peers, make a splash, you ARE your reputation, be better than everyone else!)
^^These are the values that dominate the minds of capitalistic individuals, not people who explore consciousness expansion through cannabis and psychedelics: in fact the expansion of mind shows how ridiculous and toxic the above values are.
The dominant drugs in a society tell a lot about the values of the society: the types of drugs that America promotes are not chosen because they are the safest or are the most pleasurable, they are chosen because they regulate the behaviors of their consumers in a way that benefits those in power. For example,
Caffeine: has a terrible 'bill of health', with many physically damaging side effects. BUT, caffeine is effective at keeping you alert and energetic, and therefore productive, so it helps you to do things like tinkering away at an assembly line of products, or typing uninteresting data into a computer, etc. in a sort of benign daze! This increased production boost the economy, which increases the amount of wealth that "TRICKLES UP" to those in power.
Tobacco: has a terrible 'bill of health' as well. BUT, Nicotine is a mild stimulant that increases productivity as well. More importantly, though, Nicotine is more addictive than any other drug, including heroin. Therefore, Nicotine addicts will shovel out $6 or more a day for a constant supply of cigarettes, which boost the economy to TRICKLE UP.
Alcohol: this one takes the cake. I need not convince you of how horrific this is to you health, just note how you feel the day after a night of heavy drinking (the day after a cannabis/psychedelic is not even close to how shitty a hangover feels). Alcohol is also highly addictive, and therefore boosts the economy. More importantly though, alcohol has effects opposite to cannabis and psychedelics. Instead of expanding your mind, it narrows it. Your thought processes are dulled, you are stupified (just listen to an alcohol TRY to sound articulate). You do not rationalize before acting. And also, it reinforces boundaries (me vs. you = barfights, when was the last time you saw a stoner/hippy break a bong over someones head for looking at them for too long or the wrong way?)
Okay, that's pretty much the 'backbone' of why cannabis and psychedelics were vulnerable to becoming illegal in the first place in the United States, and probably explains their legal status in many other countries as well. To sum up, Cannabis and psychedelics are radically different than the socially accepted alcohol, tobacco, and caffeine. The powerful elite have remained in power because they were and are able to influence the behavior the majority of US citizens, by suppressing drugs that would 'open their minds' like cannabis and psychedelics. They do not want people consuming these mind openers, because they are sort of like 'bullshit detectors': the more you start asking questions, thinking outside of the box, acting in a way that is helpful to the humanness of yourself and others, the more you start to realize that most of the behaviors that you have been conditioned into are bullshit, are toxic and destructive, and are designed to benefit a very small percentage of the population called the elite rather than you! And this is why mind-expanding drugs will be suppressed by the elite to the utmost extent possible, and is why 50% of all prison inmates are NON-VIOLENT drug offenders.
Thank you very much for listening to my rant. I think that if supporters of mind-expanding drugs want any hope of acceptance (however unlikely, legalization is out of the question), we need to stray from the obvious 'clean bill of health' argument, and vocalize the REAL, subtle issues that dominate the situation in the background. We must expose the bullshit constantly streaming out from the elite minds, and openly tie that into the terrible war on drugs that is happening in order to have any chance of what we can truly call freedom.