One should never have to justify a personal freedom. So long as it is not infringing upon the right of another it should be inherent. If you wish, you're free to attempt to justify why it should be removed.
I concede this point. I guess I don't have a problem with idiots abusing drugs and killing themselves in the process - no sympathy from me here.
The point is (obviously) not which does more harm. Even furthermore we are not strictly talking about heroin but recreational drugs in general. Why don't you compare it to the inherent harm in consuming THC once a week? The point is, even as the US national deficit is well over $1 trillion, and states are having to borrow money to pay for things like teachers and fire departments and law enforcement, we are spending over $50 billion a year and that's on law enforcement alone, not counting prison costs and upkeep. And what have we accomplished with such a policy? We've created a an underworld where gangs, thugs, and mafia thrive, and get rich off the sale drugs. Anyone who wants it can still get it whenever they want, either with money, or violence. It's counter-productive and quite frankly a waste of taxpayer money.
You mentioned heroin in your original post so I was running with that. Sorry what's THC? You were comparing stopping someone from taking heroin (again, using the example in your original post) to telling someone what movie to watch on a Saturday night and saying that the former would, via a slippery slope, lead to the latter. I was merely pointing out how the two situations are falsely analogous.
Listen, I'm not encouraging drug use and I don't use them myself except for alcohol -- I just don't want my government holding my hand, telling me what I can and can't do, and adding to the national and state debt in the process in futile, abortive, self-righteous attempts to stop it. I find that much more morally repugnant.
It sounds to me like your objection to making drugs illegal stems from the counter-productive effects it's had in the US with some liberal ideals thrown into the mix. All I'm saying is that criminalisation on ALL drugs has worked in other countries; and it's for this reason, and the fact that I am beyond thankful to live in a relatively safe society, that I have to put aside my liberal beliefs and defer to my authoritative government on this matter. Perhaps legalisation of some recreational drugs with strict regulation would work better in the US, but I definitely do not want to see it happening in my own country.