If we have an interactionist definition of harm, preferably, one which was prealably deliberated with the community, we have no trouble applying the harm principle. — Godefroy

I got a question. Under this interactionist definition of harm, could we have some kind of coherent and unified way of explaining what all types of harmful actions have in common? For example, would we be able to provide an explanation for why taking something without someone’s permission necessarily constitutes a harm while an act like smoking weed wouldn’t necessarily constitute a harm? I’m inferring from your post that your answer would be that a particular action is harmful just in case it was considered to be harmful by a particular community(at least that’s how I understood what you were saying). My hesitations with this sort of definition of harm mostly has to do with how difficult it is to determine where a particular community starts and where the community ends. For example, do we subdivide communities into nation states or do we subdivide them into something smaller like towns or cities? On the issue of weed legalization, I think there can be huge differences regarding the opinions that different communities will have regarding how often weed causes harm to others.

In addition, I think some communities, especially more religious ones, may conceptualize harm as something that could be impersonal and victimless. For example, they might say that smoking weed causes harm because it upsets God or because it violates the sanctity of the community even if done completely privately. I think this consideration also could potentially pose another big challenge to the harm principle if we were to reject my phenomenological definition of harm.

Well smoking weed wouldn't be what caused the car accident and wheelchair harm. Pretty obviously it was something to do with the driving, possibly from the weed but not necessarily. — DingoJones

What are you saying? That the driver was a poor driver anyway, and smoking weed was only the final straw in their driving ineptitude?

Running people over isn’t a victimless crime, but smoking pot is.

People who smoke pot hurt themselves, so they are the victims, so smoking pot isn't "a victimless crime".

Also, people critical of smoking pot or its legalisation have to be critical of drinking alcohol or its legalisation first if they want to be taken seriously.

I'm critical of all substances and activities that in any way diminish a person's ability to drive safely.

What are you saying? That the driver was a poor driver anyway, and smoking weed was only the final straw in their driving ineptitude? — baker

What I meant by that was that he was driving while high, as opposed to just being high. The problem, maybe, is driving while high. The fact that people might be getting hurt by high drivers doesnt mean getting high is wrong, it would mean getting high and driving is wrong.

People who smoke pot hurt themselves, so they are the victims, so smoking pot isn't "a victimless crime". — baker

Victims of what?
Also, alcohol. Any criticisms you have about pot use also apply to alcohol, plus more since alcohol is clearly worse on every level. Do you think alcohol should be illegal?

I'm critical of all substances and activities that in any way diminish a person's ability to drive safely. — baker

You seemed to be using the supposed accidents caused by weed as a reason people shouldn't smoke it or it should be illegal, did I misunderstand you?
Also, many things diminish driving, lack of sleep, fighting with your girlfriend, fussing with the radio, yelling at some guy who cut you off etc, none of which are activities you shouldn't do, they are things you should be careful about when driving.
And that's IF you could show that weed affects driving with significant diminished safety which the data doesnt indicate.

Under this interactionist definition of harm, could we have some kind of coherent and unified way of explaining what all types of harmful actions have in common? — TheHedoMinimalist

The fact that the harm was interactionally derived guaranteed previsibility which is necessary for a principle to work. The harm must not be phenomenologically open in order for the principle to work, it must be phenomenologically closed.

I think some communities, especially more religious ones, may conceptualize harm as something that could be impersonal and victimless. — TheHedoMinimalist

Your problem is with the harm, or more precisely, with actions that truly concern only the self and more specifically, whether or not actions really can be private because of the social embeddedness of human actions. Two problems emerge with assessing the significance of harms : which harms are relevant and the privacy of the action that caused the harm.

The relevance of harm is hardly a settled matter. Are harms instigated by false beliefs real harms? Is a harm a mental state or are there other relevant matters for assessing harm? Furthermore, does the way in which the harm was brought about relevant? Should we think that merely allowing a bad thing to happen is sufficient in order to consider constraining it? Or should we in fact think that only doing harm is relevant? Maybe we should criminalize willful doing of harm. But does willfully allowing harm essentially equate to willfully doing harm?

For example, they might say that smoking weed causes harm because it upsets God or because it violates the sanctity of the community even if done completely privately. — TheHedoMinimalist

If privacy matters, even if it hurts your values, you can be against criminalization of that act but be morally against the commission of the particular act. See for example the prime minister of Canada, P-E Trudeau in 1969 when he decriminalized homosexual intercourse :

We don’t allow homosexuality, we’re just saying we’re not going to punish. We will not send the police to the bedrooms to see what is going on between consenting adults in private. […] We are taking the idea of ​​sin out of the Criminal Code. — Pierre E. Trudeau

Another commentator, Thérèse Casgrain, commented on a case where people were imprisoned :

It is inconceivable that we so arbitrarily lock up an individual for acts which do not violate public decency since they are committed privately or against the integrity of young people, since they were committed between consenting adults. — Thérèse Casgrain

Maybe Trudeau and Casgrain were against homosexual intercourse, but privacy did matter when assessing the significance of the harm committed. It seemed clear, in that case, that actions between two consenting individual were not a public affair, because homosexual intercourse is conceptualized as a singular event which did not concern public law, even though it shocked more than the two persons involved in the action.

Thus said, I hardly see how these matters actually affect our agreement over the the harm principle. We can agree with the harm principle without agreeing to a common theory of the significance of harm. We can agree that 1) an action which only hurts me 2) jand does not impact someone else 3) in a significant manner in order to constitute it as harm, should not be criminalized. We can agree on the principle (albeit a very reinterpreted one) without agreeing with what precisely is a significant harm comprised in condition 3. Therefore, the harm principle isn’t in any way vague about what conditions are relevant for prohibition, but it is quite harder for it the be specific about what it prohibits.

Thus said, I hardly see how these matters actually affect our agreement over the the harm principle. We can agree with the harm principle without agreeing to a common theory of the significance of harm. We can agree that 1) an action which only hurts me 2) jand does not impact someone else 3) in a significant manner in order to constitute it as harm, should not be criminalized. We can agree on the principle (albeit a very reinterpreted one) without agreeing with what precisely is a significant harm comprised in condition 3. Therefore, the harm principle isn’t in any way vague about what conditions are relevant for prohibition, but it is quite harder for it the be specific about what it prohibits. — Godefroy

That’s a pretty good point. I think I was wrong to call my thread “The Vagueness of The Harm Principle” as this doesn’t actually seem to properly describe the issue that I have with certain kinds of libertarians applying the harm principle. The problem doesn’t seem to lie with the principle itself as it really doesn’t seem to be vague per se —rather I think that the assumption that weed doesn’t cause harm to others is what really seems suspect to me.

And that's IF you could show that weed affects driving with significant diminished safety which the data doesnt indicate. — DingoJones

If you end up in a wheelchair after being run over by a pot smoking driver, we can then have a discussion about the relevance of "significant enough" probabilities.

If thats your situation then I’m sorry that happened to you but it doesnt mean smoking pot is bad, it would at best mean smoking pot and driving is bad. At best, because you would have to show that the pot is what caused the accident. The data doesnt usually back that up, in all the recorded cases I’ve seen where a person was high and got into a car accident they were also drunk.

Thank heavens you've got the alcohol to blame! And not perhaps that smoking pot induced the person to a number of other bad choices, such as drinking and driving.

Ok, well you are clearly not interested in discussion. You have no rational reason for your claims and have a clear bias against pot.

*sigh*