When is it appropriate to institute a quarantine on an individual? This has been on my mind quite a bit for the past few weeks. To my mind, this would fall under the same criteria as any other use of force. With the non-aggression principle, the only valid use of force is defensive force, and you should use the minimum force necessary. Someone with a contagious disease is a threat to others’ health and lives. So others are justified in using force to control that threat, and impose a quarantine.
However, to be just, there has to be a rational threat from the person. Just that they give you a bad feeling is not justification for using force. This is the case with the current quarantines of asymptomatic people who have been near people with Ebola. The evidence is in: Ebola is not casually contagious in asymptomatic individuals. Duncan didn’t spread Ebola to anyone other than nurses working in very close contact with him when he was very sick. None of his casual contacts caught the disease, even his family living in the same apartment never caught Ebola. In the absence of evidence that these people pose an immediate and significant threat to others, imposing a quarantine is unjust.
Also, some seem to have forgotten what the word “voluntary” means. On NPR a few days ago, they said that people would need to “voluntarily quarantine” themselves in their house, or they would be subject to a mandatory quarantine. How does that sentence make any sense?! If you have to lock yourself in, or others will lock you in, that would be a mandatory quarantine already, wouldn’t it?