Regardless of how effective drugs like LSD and psilocybin are, they make it difficult to maintain traditional societal hierarchies of power and control and thus will be stamped out.
How? How does making you see things that aren't real challenge any hierarchies?
While LSD and psilocybin do sometimes cause people to hallucinate, this is only one small part of the psychedelic experience. The real value is in how the drugs change your thinking. It would take an entire book to explain this, but here are a few YouTube videos to give you the basic idea:
http://www.youtube.com/watch?v=9c8an2XZ3MU
http://www.youtube.com/watch?v=rLXmE_hxCcg
http://www.youtube.com/watch?v=KeqmKwsvM58
It's difficult to explain how exactly they challenge hierarchies, but the 35,000 foot overview would be that psychedelics tend to make one more prosocial, whereas hierarchies tend to be fueled by antisocial behaviors. They also tend to give one self-confidence and internalize one's locus of control, whereas again hierarchies can only exist when people lack self-confidence and have relatively external locii of control. Essentially hierarchies are built on the backs of those trying to fill some sort of void in their lives, whereas psychedelics undermine this by giving one perspective and making one whole.
Here is the best description I've found:
"What is the psychedelic experience? For me it's the full and overwhelming realization of all the beauty, love, and pain, the wonder and possibility, of the human experience. For the first time you see your life truly objectively, what's going wrong, and what's going right. You grasp and grapple with how you can do better, and you are overcome by the newfound desire to strengthen your community, your relationships, and your karma. And so it proceeds for the next 4 to 6 hours.
And as the raw intensity of the experience fades, it leaves behind this lasting sense of optimism, hope, and strength, a sense that something essential has been renewed, replenished, and maybe even reborn. Above all you're left with a need to make things better, to help others, and to improve your life. And at last you have the strength and vigor you need, without which action was not possible.
The morning after taking LSD it's not uncommon for people to re-enroll in school, restart their job search, or reunite with old friends. There is this sense that whatever was holding us back is dead, we've come to terms with it, and now the power is back in our hands.
It's an experience that will shake your faith in society while simultaneously restoring your faith in yourself, the meaningfulness of existence, and your ability to make a difference.
http://www.youtube.com/watch?v=k6Ps_MBXEdA
(As an aside, I don't take YouTube very seriously on the whole unless I happen to know the specific person who made and uploaded the videos.)
He wasn't joking you know.....why do you think such normally respectable people talk about this...hell man, I'm likely more conservative than you!
It should be said that a trip can also be the worst experience of your life; you can live through the biggest fears you could not imagine that even existed. I have been tripping about five times in my life and most of the trips were of mixed nature. I have felt the supreme beauty and I have felt the supreme fear. In retrospective both are worth it.
A hallucination is the perception of something that is not there at all, and it generally means that the thing is sincerely perceived as real.
Psychedelic experiences typically fulfil neither of these criteria.
To call such experiences mere "hallucinations" or "perceptual disturbances" is both reductionist and dismissive.
However I think it's appropriate vocabulary when attempting objective analysis of neurological/psychological phenomena. Reductionism is an inevitable and valid criticism of any such analysis.
(When I said "real" in this instance I was referring to the physical existence of objects perceived, your ability to reach out and touch them. I wasn't trying to make a value judgement about the validity or authenticity of anyones subjective experiences.)
Without getting in to a deep conversation on objectivity, neurology, and psychology, I'll just say that I don't think these issues are so clear cut as to allow anyone to definitively say that he's on the side of truth and the phenomena he describes are "nothing but X", whatever that "X" may be.
"When I said "real" in this instance I was referring to the physical existence of objects perceived, your ability to reach out and touch them."
There are plenty of things that, even according to the "scientific" world view, purportedly exist and yet can't be touched or directly percieved, such as x-rays and atoms.