I would say the mind is complex and multifaceted and interconnected enough that the odds of any given psychoactive drug having long term negative side effects beyond the intended one, at least in some proportion of those taking it, should be close to 100%. Once I asked my doctor whether something could be a side effect of an over-the-counter medicine, and his response was, "In the right patient, any drug can have any effect." Not literally true, but a good heuristic.
I was prescribed modafinil from 2012-2016 for a sleep disorder no one could identify. It's probably the only reason I was able to keep my job and my relationship (now marriage), or was able to safely drive. The only side effect I noticed was some increased moodiness.
Unfortunately the extra energy and focus also masked other underlying issues and symptoms. Until I went off the medication I didn't realize I'd been in a state of depression, possibly since as far back as 2007. Because it happened so gradually, and because I'd been able to function day to day, I didn't notice that I'd pretty much stopped having emotions, that my reaction times were slower, and that my senses and memory and thinking were dulled (it got bad enough that several times I and others thought I might have had a stroke). It's taken years of therapy (and later, bupropion) to function normally again.
None of that was a chemical side effect of modafinil in the way you're asking about, but if I had been thinking psychologically instead of pharmacologically I could have better identified what was going on and avoided years of suffering (my own and my wife's).
My point is: even if you have no adverse biological reactions to something, the medium and long term effects of a psychoactive substance have a good chance of being dominated by second-order effects resulting from how changes in your thinking affect how you live and experience your life, in ways that are extremely hard to predict and very individually variable. And because those things can change who you become and not just how you think, they will tend to last long after you stop taking the substance.
What does "negligible" mean here? Negligible on what time scale? Because if the overarching question is "How do we stop or reverse aging to become amortal?" then any process of monotonic irreversible decline becomes important eventually.
I'll ask you the same question that clarified my thinking on this: what is it you want from your free will? For me, it's that I want to be the one to decide my actions.
Do you want your actions to follow no laws at all? Then they're essentially random. You cannot possibly be in control of what you do, in that world.
Since I don't think most people want that, what kind of laws do you want them to follow? Because whatever laws determine your actions, and whatever you are, you exist within them, not outside them. In order for 'you' to freely choose your actions, they must be sufficient to determine what you choose.
Do you want to not be influenced by anything outside yourself? Then you have no ability to take account of the state of the outside world in deciding what to do. You've given up any chance of steering the future state of the world you live in, or of achieving goals involving anything outside your own body.
What I want is for the primary locus of control, the proximal cause of my actions, to be within me. I want to minimize certain kinds of external influence on my decision-making processes, which I loosely categorize under labels like "coercion" or "violence" and so on, despite not having or expecting precise definitions of those things. That list also includes minimizing certain biases built into me by history and evolution from before I was conscious, which is how I first ended up here on lesswrong. None of this has much of anything to do with what the laws of physics are. I have a lot of that, and I get more of it the more I learn about what things influence and determine my thoughts, choices, and actions.
4000 IU daily is the safe upper limit for a daily dose according to the NIH. The body buffers D3 by building up stores in the spring and summer. So in order to see benefit any time soon at all, an initial one-time only large loading dose(or doses) should be taken, ideally with a fatty meal. I'm not sure if providing a conservative number here would be against the forum rules.
I can't comment on what anyone should take, but I'm a ~215 lb male, and a few years ago (age 30) I was diagnosed with a mild Vitamin D deficiency and prescribed 50,000 IU once per week for either one or two months.
Yeah, before I started I considered adding "GEB gets more popular" to my list, but then forgot to include it.
What are your specific goals here?
If you want to close a gap between who you believe you are and how you present yourselves to others in certain situations, I think that there's a good chance coaching can help.
If you want to change who you are to match your own ideal of who you want to be, that may be possible, but much harder.
If you want to get dates, it's probably possible to learn to fake your way well enough to do that. But be careful when, where, and how you do that, because it's very easy for that path to get pretty dark.
If you want to find a partner, though, you don't just want to be attractive to "women," you want to find the subset of women who will be a good match for you, and around whom you can be yourself. See https://putanumonit.com/2016/02/03/015-dating_1/ for a much better discussion than I could ever manage.
I think, like every other proposed utopia to date, any such system would 1) be horrible to live under, since it's would need to be a near-totalitarian system ruling over a large, non-homogeneous population nonconsensually, and 2) fall apart in five minutes through in-fighting, since no one actually has the ability to control what billions of people think and believe and do.
Also, your question depends heavily on drawing a boundary between culture and ideology that I suspect is fuzzier in practice than that. Suppose you succeed in unifying every human, and we all agree to live by a single set of ideals. What happens next? We have to figure out how to apply them, and how to resolve disagreements about how to apply them, because any ideals worth living by are complicated, and humans are not logically omniscient. We have to teach the next generation those ideals, and persuade or coerce them to live by them. Even if you define your system with mathematical precision, and go full Shining Garden, average humans will just be abiding by the output of a decision-making process they can't independently reproduce, and (after a while) much of which happened before they were born - aka culture.
Side note: the use of passive voice in your question is a big red flag for me. Who does the removing?
Similarly, "the system of opposing beliefs" sidesteps the whole problem that (like Moloch), it isn't so much a system, no one instantiated it, it's just a consequence of us all being able to think and learn and not leading identical lives or having identical drives, wants, and needs.
Still, my answer is: trivially yes, that scenario would result in unification, but by default I would be extremely strongly opposed to any path that led in that direction, and would need a heck of a lot of convincing to even consider any proposal of that sort.
I am 100% in agreement with TheMajor's and Mathisco's comments on power, status, and enforcing cooperation.
I just wanted to comment on these lines:
Having leaders suppress their own opinions at the start of deliberations and explicitly express a desire to hear new informationSetting cultural norms that encourage critical thinking and productive disagreement
Implementing this requires a greater degree of trust in the honesty and intentions of management, fellow employees, and future outcomes of things like promotion and hiring/firing decisions than I have ever experienced anywhere I've worked, or anywhere most people I know have worked. Even if your boss really does believe this would be a better way to make decisions, doing something different opens up everyone involved to being first in line for scapegoating when something goes wrong, and last in line for promotion if they're seen as a threat to the jobs of the higher-ups. In most meetings I've been in, everyone with any savvy at all knows this, and will only express their own opinions if they're already very secure in their status within a meeting (or if they're relative outsiders or newcomers able to frame opinion or criticism as a question).
I honestly wasn't sure how to answer the memory question, because although I remember lots of things well, they don't seem to be organized or attached to each other the way they seem to be for other people around me. A person's name, face, and story might all be things I know, but I don't easily link them to each other. I remember the (complicated) names of characters from hundreds of fantasy and sci-fi novels I read 10-20 years ago, and have near-photographic memory of the location of every item in my refrigerator (yes, refrigerator specifically, not the pantry cabinets around it), but routinely forget where I put my keys/phone/wallet/mug/etc. The other night I was talking about a bunch of similar places I've been along a route, and I remembered images of each one, and the set of street names they were all on, but had no idea which was which, or where they were geographically in relation to each other.
As far as unusual mental experience, I went through a years-long period of depression without realizing it had happened. I gradually lost most emotions and didn't notice. I lost much of my senses of smell and taste. I lost a lot of my ability to distinguish specific sounds and visual features in my environment (I'd look right at a field and not see the bright red flowers, or in one notable instance, the tree that had fallen into a house). At its worst I thought I had had a stroke, because one day my reaction time slowed by at least a factor of 2-3, I had trouble doing basic tasks like paying at the grocery store, and when people spoke to me I sometimes heard the individual sounds but they didn't form words in my head. That part lasted about a week. All of those symptoms went away in one moment three days after I started taking antidepressants, and since I got the dosage right, they've never been back for more than a few hours at times when I missed a dose and am extremely stressed or tired. Also in that first month on antidepressants I reread Mastering the Core Teachings of the Buddha and made more progress in my meditation practice than I ever had before or since (extremely clear experiences of what he describes as all eight jhanas and all the stages leading up to stream entry), like I cleared a blockage and released a flood of potential I'd been building up for years.