Are there any philosophical arguments against self-harm? There’s the quick utilitarian response: self harm is wrong if the pain you cause exceeds the benefit. So, even if you don’t care about the harm to yourself, if your family or friends are driven to great pain by your lifestyle that exceeds the joy you receive from living your autonomous life style then you are doing wrong. So, we can imagine the pain caused to the heroin addict ‘s parents by constant worry could lead to its condemnation.
BUT, There’s a more interesting Kantian style answer though. This is from David Brink “ The self is not to be identified with any desire or any series or set of desires; moral personality consists in the ability to subject appetites and desires to a process of deliberative endorsement and to form new desires as the result of such deliberations. So the self essentially includes deliberative capacities, and if responsible action expresses the self, it must exercise these deliberative capacities. ... The proper aim of deliberation is a life of activities that embody rational or deliberative control of thought and action.”
I think what he’s trying to say here is that living according to your base desires, let’s say drinking beer all day, or whatnot is not a true exercise of your rational capabilities. Therefore, it violates your very nature as a rational human being. The exercise of morality is tied up in being a rational being who deliberates. If you choose to not deliberate and just give in to your quickest desires, you are morally wrong because you are violating your very rational, moral nature that qualifies you as an adult human.
That said, a bohemian can live a very fulfilling life dedicated to art and creativity. Not every bohemian is necessarily Charles Burkowski on a weekend bender.