To the folks who still use drugs: When will enough be enough? Surely you don't plan on using drugs for the rest of your life?
When the doors are fully opened, and are kept open (which is done through spiritual practice during/after the experiences).
Any noble or pious society wouldn’t need this. If the individual could contribute to such a society then that's great.
Perhaps they don't need it, but every
noble and pious society, with very few exceptions, has used such things. Greeks, Romans, Japanese, Chinese, Egyptians, Babylonians, Carthaginians, Aztecs, Mayans (all Native Amerinds, actually) - the list is indefinite, because as more cultures rise after this one's fall, they'll be turning to these sources of knowledge for guidance, just as our ancestors did.
Drugs may afford spiritual insight (LSD), increase abstraction of thought (Marijuana), or enhance one's focus (Amphetamines) but do they increase your IQ? Certainly not.
I'm aware that cannabis, for example, should not be taken by adolescents, due to its potentially negative effects on brain development. However, there seems to be much less, if not no, damage done to a fully formed brain through consuming cannabis (though excessive amounts of CO from smoking can obviously cause problems, like the monkey suffocation they used to parade as "death by marijuana"). I wouldn't want my daughter or son taking any other similar substance until they are physically, mentally, and emotionally mature/healthy enough to make the most out of it. However, after that point, I can find nothing to suggest that any of these substances might be harmful in any meaningful way, and very much to suggest that their consumption can generate huge benefits for humans.
Your assertion that drug-taking cannot enhance IQ is baseless. You could provide no source for that claim, since we don't yet even know all of the psychedelic narcotics. As things stand, there are synthetic drugs which increase (temporarily?) your IQ (e.g. nootropics); there may well be naturally occurring substances which do the same (and may even trip you out, maaaan).
Furthermore, the more I understand, the less important IQ is. It is a measure of intelligence, but is not intelligence itself; at that, it cannot denote wisdom, and the wisest might appear to have no intelligence (which might be true!).
As a mild aside: there seems to be a hell of a lot of wimpish, modernistic thinking going on around here. If you're concerned so much about your physical, mental, or social wellbeing that you don't want to push the boundaries, that's fine: you probably shouldn't. That said, don't try to make yourselves out as being somehow "better" for allowing insecurities. I could not live with myself if I left so grand an avenue unexplored; it is in my nature to accrue experience, in whatever way. Life is for living, not for finding excuses not to live!
Here's a very small list of things which entheogens have helped me achieve (or, have suggested might be a good idea): regular (daily) meditation; no more alcohol; greater appreciation of my parents, as well as others around me; growing plants in my home; improved range of composition; spiritual insights along Sufi lines (the Way of the Heart seems to be mine); greater "connection" with my body, with others, with animals and plants, and even some objects; greater fluidity/ease of thinking; comfort in day-to-day life. These are not temporal effects; rather, they have lasted, some of them for over two years. It's more about the way in which one interacts with the world than about any one specific skill or set of skills; my relationship with the world has been made more whole/inclusive due to the use of these substances.
Evidently, smoking cannabis is a bad idea, in the long run. Evidently, taking
cannabis is a great idea!