At least for novice users and for the most dangerous hallucinogens such as bath salts or PCP. The restricted settings I am referring to is in a facility where you would be locked in for the entire high and would be watched by trainted professionals.
This could save a lot of lives lost doing these things on the street.
They are illegal because they help break down cultural programming. Alcohol, tobacco, coffee and sugar are acceptable addictive substances that not only allows cultures/governments to control you, but also lines the pockets of corporations who mass produces them to become so powerful, they can influence government decision-making. Furthermore, psychedelics would pose less of a danger to society in comparison to the most evil of drugs - alcohol.
There are some drugs that produce only minor effects and do not heavily impair someone in a way that causes them to be a danger to others. If they are not a danger to others, people should be able to do whatever they want, including taking psychedelic drugs. The real question is which drugs would fall under this category.
First a definition of drugs from the Shorter Oxford English Dictionary: "Any substance that affects the physical or mental functioning of a living organism"
The drugs most adults, and many children, use in our society are alcohol, tobacco, sugar and caffeine. They have all been proven to be addictive (there is still some debate about whether sugar is addictive, but it seems likely that it is), to be able to cause deadly overdoses (in sugar this only applies to a percentage of people, mostly those with diabetes, usually caused by sugar consumption), and to lead to a number of serious diseases and death in a large percentage of long term users. In addition, both long and short term behavior patterns may be changed through the use of these substances, generally in negative ways. Alcohol often precipitates violence, caffeine and nicotine have a tendency to increase irritability, stress levels and anxiety. In spite of how dangerous, damaging to relationships and society-at-large these drugs are when misused, I do not feel they should be illegal simply because human beings have a right to decide what they want to put in their bodies, and it is not my business or anyone else's to tell them they can't use a drug simply because I think it's bad for them or that they MIGHT abuse it somehow.
I feel the same way about psychedelics, only I am shocked that they were ever made illegal. All psychedelics are different, but very few of them are as harmful as any of the legal drugs mentioned above. Let's take psilocybin mushrooms as an example. They have been used by humans since pre-historic times and were even involved in one way or another in the formation of many religions.
Here's what we know:
1)Unlike alcohol, tobacco, caffeine and probably sugar, they are non-addictive. In a number of studies it has been shown that experiences had under the influence of psilocybin mushrooms are often reported as being among the top five or so important and meaningful positive experiences the user has ever had, and yet, after having such an experience, there is no need to take it again. People may want to experience it again occasionally, out of curiosity, but there is absolutely zero evidence that mushrooms are addictive.
2) There are no known cases of death by mushroom overdose. The average person would have to eat at least a few pounds of dried mushrooms to approach the potentially lethal dose determined by experiments on mice.
3) Psilocybin is not known to cause any lasting physical or mental issues. There are drug interactions that should be observed, and people with mental illness should not use the drug as it may exacerbate pre-existing conditions. But it should be noted that psilocybin, LSD, and MDMA have been studied as treatments for a number of personality disorders and mental conditions with positive results.
4) I'm out of room, but most psychedelics tend to produce positive changes in behavior when used responsibly.