Some recent comments have faulted people (like me) for not being "principled libertarians" because we support various restrictions in a time of epidemic, including restrictions that we agree are extraordinarily burdensome. As it happens, I don't claim to be a principled libertarian: There's a reason the subheader of the blog says "Often libertarian" (though of course that reflects the aggregate of the cobloggers as well). But more broadly, I think that many facets of liberty rest on certain assumptions, and sometimes can't extend to situations where those assumptions don't apply.

Some examples, of course, are familiar. Sexual liberty is very important, for instance (as a matter of libertarian principles, whether or not you think the U.S. Constitution is properly interpreted as protecting it). But it rests on assumptions of individual capacity to make potentially risky decisions that might not apply to, say, young children, or mentally handicapped people. Likewise, the right to procreate is very important. But if we were living on a spaceship that was limited to recycling a sharply constrained amount of air and food, that might call for limits on the number of children one has that wouldn't be justifiable in our current world of plenty.

Liberty of movement and of physical association—coming together for political, religious, social, professional, recreational, or other purposes—is likewise tremendously important. "The right of the people peaceably to assemble, and to petition the Government for a redress of grievances" is just one particular express elaboration of this liberty. But the premise behind the liberty is that people assembling together can choose to be "peaceable," and thus physically safe for each other and for bystanders, and we should punish only those who deliberately abuse the right (by acting non-peaceably).

Contagious disease, unfortunately, has the property that I can sicken or even kill you with it entirely inadvertently, without any choice on my part. It's not like carrying a gun, which I might misuse but which I can choose to use properly. It's like carrying a gun that every so often (and largely unavoidably) just shoots a bullet in a random direction, without my pulling the trigger.

What's more, not only can I sicken or kill you when you've voluntarily agreed to be around me (e.g., agreed to go to a political rally or a religious service where many potentially infected people gather): I can end up helping cause the sickness or death of other parties with whom you later come into contact, or those even more steps removed.

Libertarians often articulate the basic principle that people cannot initiate the use of force or fraud against others. But I don't think it makes sense to see the "force" prong as limited to deliberate injury; causing sickness or death to others inadvertently may be less morally culpable, but it is just as injurious. Right now, our bodies (at least until the availability of highly reliable tests for not being infected, or, better yet, being immune) are, for most of us, a potential source of infection and thus injury and death to third parties. The normal conditions that have justified liberty of movement and assembly in the U.S. for all my life unfortunately do not apply right now.

Now of course this raises all sorts of complicated questions. Obviously liberty emerged at a time when contagious diseases were both much more common and more deadly than they are today, because of the absence of effective prevention and treatment—consider, for instance, tuberculosis. Some amount of unintended risk created for others was seen as acceptable.

My sense is that our society is now insisting on a much lower threshold of acceptable risk, perhaps because we have gotten so used to a very low death toll from casually communicated illnesses (mostly from the flu and similar diseases). One can certainly debate whether we have adopted too low a threshold: Perhaps massive restraints on travel and assembly might be acceptable for diseases with the lethality of Ebola or some unvaccinatable-against mutation of smallpox, but shouldn't be acceptable for this strain of coronavirus.

And of course this is further complicated by the uncertainty of just how reliable various protective measures might be: For instance, if it we were confident that wearing a certain kind of mask would prevent the wearer from infecting others, then there would be much less justification for banning mask-wearers from traveling and gathering with others. Unfortunately, so much remains unknown about the facts here.

But the broader point is that the normal conditions that justify liberty of movement and travel—that make this liberty consistent with the libertarian judgments that each of us should have the right to do things that don't physically harm others—are regrettably not present when each of us (with no conscious choice on our parts) is potentially highly lethal to people around us. However peaceable we might be in our intentions, our assembling is a physical threat. Our judgments about liberty, I think, need to reflect that.