- A driver refuses to wear a seatbelt
- A parent fails to secure their young child's seatbelt
- Someone drives drunk
When I think of health claims, I don't care so much if a person chooses to treat themselves with whatever they think were work. If they have cancer and want to cure it by homoeopathy, it's their funeral. Think that magnets or shark cartlidge will cure a bad knee? A fool and their money are soon parted. This is the equivalent of someone not wearing their seatbelt. While there might be other factors to consider (such as individuals organising together to claim that seatbelts are a propaganda device of Big Auto that cost countless lives), it's their freedom to make that choice.
The child case is a bit more tricky. After all, parents do have responsibility for their children, but it's also recognised that a child has rights beyond the parent's dominion. A parent using prayer to cure a sick child while there's actual medical intervention that could help the child a gross violation of that child's liberty. Not strapping a child in securely may be harmless in most trips, but seatbelts aren't there for most cases - they are there for when things go horribly wrong.
Many diseases are communicable. Someone infected with the flu deciding to come to work because they're "taking echinacea" is shirking their social responsibility and putting others at risk. Like the drunk driving scenario, there are potential consequences for people who didn't make that choice. Vaccines are a good example of this, as not only is it putting the individual at risk, but it also puts others at risk (as recent epidemics have sadly shown).
The idea that it's one's personal freedom to choose what "treatments" they wish to undergo only works when that ailment/treatment is only putting themselves at risk. For the latter two cases, it should be uncontroversial that it's not just their own freedom at play. It is uncontroversial in the seatbelt case because people agree that seatbelts save lives. Yet if someone believed that seatbelts not only have no effect, but actually caused harm, how do you separate out that they should be forced to use a seatbelt with their child? Or if they believed that they were a good driver no matter how much they drank, would it be seen as anything other than intrusion that they would not be allowed on the road in that condition?
The difference between driving and alt-med is that people don't dispute the facts in driving. Alt-med is filled with science-denial and paranoid conspiracies in order to justify the harm that they cause. The personal freedom many argue for harms the personal freedom of others, so they just deny the facts instead.