Liberty, Security, and Fourier Transforms 

            Fourier transforms define pairs of measurable things that have a complementary relationship. You can accurately define one or the other, but not both at the same time. The most common example is in signal processing, as in the electronics of recording studios and sound systems. When recording music, you must constantly strike a balance between mostly knowing what the note is and mostly knowing when it occurred. You can’t know both precisely at once. This is not intuitive because the “mostly” is good enough for human ears if you get it right, so we never notice. 

           The Fourier transform itself is an equation that gives the exact amounts of “mostly” that we can get away with on either side. This is critical knowledge in making sure that Adelle or Kendrick Lamar sounds in your headphones as much as possible the way each sounded when they originally performed into a microphone…or maybe better. 

           I think there must be a Fourier transform for other pairs of things that are less easily measurable than sound signals but clearly have the same kind of complimentary relationship. One of those pairs is liberty and security. 

           Too often we are told that some policy or action will make us both more free and more safe. That is nonsense. Since prehistoric times humans, individually and collectively, have constantly made decisions that trade freedom for safety. Weaker individuals serve stronger ones to gain protection from other stronger individuals. Strong or weak individuals cooperate to increase protection from other cooperating individuals. In cooperating each person agrees to reduce individual freedom by following decisions of the group or its leader. This is the fundamental dynamic of tribes. It’s true of any organization, from girl scouts to gun clubs. If we do it voluntarily, we don’t notice losing the freedom so much. But we still do. 

           In complex societies, we create laws that reduce our freedoms to enhance our safety. A traffic light tells each of us when to cross an intersection rather than just doing it when we feel like it. Often collective freedoms are sacrificed for collective safety. 

           Classical libertarianism (which has only a superficial resemblance to Libertarians today) tried to deal with this by setting guidelines for making these tradeoffs. That’s important, because we all want as much individual freedom as is compatible with enough safety to enjoy it. The problem today isn’t that we disagree on how to decide the tradeoffs, it’s that we are in denial that such a tradeoff exists at all. We want to believe that if we do things “right”, we will be both maximally free and maximally safe. 

           This is a recipe for disaster. If we can’t at the same time know precisely what note someone sang and when they sang it, doesn’t that indicate that some of these other problems might be fundamentally unresolvable also? 

           The good news is that we don’t have to resolve this precisely. We just have to be “good enough for humans”, and we get to decide what that means. To do that, we first must accept that every gain in freedom sacrifices some safety and vice versa. Second, in each situation we must try to identify where the freedom is gained and where the safety is lost. This is not simple, because they may not be aligned. Something that increases safety or freedom for one part of society may decrease that for another—though only in the near term. Eventually serious inequality of anything destabilizes society and reduces the benefit for everyone. If we can get through all this, we then argue amongst ourselves about the relative benefits of the freedom and the safety and come to a consensus on what to do. 

           This isn’t easy, but until we can frame the conversation in these terms, we don’t have a chance. Maybe someone will someday discover, albeit roughly, a Fourier transform that defines the limits of the liberty-security tradeoff. That could be a big help, but only if we open our minds to it. Whether or not we ever have numbers on it, we must realize the basic truth that when it comes to safety and freedom, it’s always a balancing act. We can’t maximize both. 

Hugh Moffatt 
Watertown, Massachusetts 
February 5, 2022