Fear is a besetting emotion. It is with us always. It is also a universal feature of animal life. Fear motivates like no other emotion. It is unpleasant, intense, and disruptive. We do well to understand it. The aspect of fear I want to focus on is its extremely labile character (OED: “liable to change, easily altered”). It is labile along two dimensions: abruptness of change, and flexibility of object. You can feel an intense and overwhelming fear at a particular time and instantly cease to feel it if circumstances suddenly change: that is, if your beliefs change (beliefs are also highly labile). This is biologically intelligible: circumstances can change rapidly and we need to update our fear emotions accordingly. You thought you were about to be attacked by a bear but you suddenly realize it is only a bush: the emotion evaporates in the instant, with barely an echo remaining. Similarly the onset can be sudden, as when what looks like a fallen branch turns out to be a rattlesnake. Again, this is evolutionarily predictable. Other emotions have more lag time, more inertia, especially attachment and love: they start more gradually, build up, and take time to dissipate. Fear is like pain: it can abruptly end and begin—and pain is one of the things we most fear (death being the other thing). Love isn’t like a sensation at all in that it has no such well-defined temporal boundaries; the closest thing to it are sensations of pleasure, which may take time to take hold and time to dissolve. But fear is highly responsive to changing circumstances—hyper-labile. It is nimble, belief-dependent, and easily triggered and terminated. Phobias are a case in point: the fear can be intense in the presence of the feared object, but it quickly subsides once the object is removed. The phobic subject is not continuously assailed by fear of the phobic object if it is kept at a safe distance, but the onset is sudden when confronted by it. The point of fear is to be switched on quickly when the occasion demands and not to hang around once the danger has passed or receded.
But it is the second labile aspect of fear that really makes it stand out. Here again there are two expressions of this: variability of object and object redirection. You can be afraid of almost anything and of nearly everything; fear is not choosy. There are people who are deathly afraid of celery or butterflies; many people are terrified of non-existent objects; the unknown inspires general dread. We are all afraid of death, disease, poverty, loneliness, failure, and rejection. I am not at all happy with heights. Again, love is far choosier: you can’t love just anything. This feature of fear seems rather counter-evolutionary: why install such an undiscriminating fight-or-flight response? Where is the biological payoff in celery phobia? Perhaps this is an overshoot of the need for flexibility of object; it is certainly puzzling (hence phobias are regarded as irrational). Freud had elaborate theories about why certain phobias exist (celery as a symbol of something genuinely dangerous). But the second aspect is particularly peculiar (in both senses)—what I called object redirection. This is a curious psychological phenomenon, though evidently common enough. I mean the tendency of fear to shift its object from one thing to another for obscure reasons. Suppose you are afraid of becoming unemployed: you then find yourself afraid of individuals of a certain ethnic group. Your fear has shifted from your own joblessness to certain people. Or you fear the police and find yourself afraid of anyone in uniform. You might recognize this as irrational but your fear mechanism has other ideas. Trauma works like this: it spreads fear around indiscriminately. Thus you are easily triggered by situations with only a slight resemblance to the original traumatic event: from gunfire to firecrackers, from near drowning to water in general. The fear spreads itself wildly from one object to another, finding similarities everywhere. You might be afraid of anyone with a certain accent because of a bad experience with someone with that accent years earlier. The spread is not entirely unintelligible, but it is certainly extreme and unruly. Whole populations can become fixated on a certain fear object as a result of their other fears. This is fear overflow, fear misdirection, fear shift. Fear will readily swap one fear object for another without much regard for rational justification. It is just too labile—too ready to attach itself to inappropriate objects. Fear fizzes away inside, searching for an outlet, and it can easily be redirected to objects not deserving it.  We need a catchy phrase for this so that its prevalence can be memorably captured (compare the phrases “confirmation bias”, “cognitive dissonance”, “sublimation”, “projection”, and the like): how about “fear shift” or “fear retargeting” or “fear transference”? It is the marked tendency of fear to latch onto anything in the general vicinity—the analogue of loving any blonde person because you love one blonde person (which is not a real thing).
We have all heard FDR’s famous statement, “The only thing we have to fear is fear itself”. Is this true—can it be true? Can we fear fear? You can be afraid that you will feel fear in the heat of battle, and you can be afraid that other people will be afraid of you and hence attack you: but can you fear fear itself? The answer would appear to be No: for what is there about fear in itself that should occasion fear? How can that emotion be a proper object of fear, any more than other emotions? Can you be frightened of hate as such (as opposed to its possible consequences)? There is nothing intrinsically dangerous about fear considered in itself: it is just a feeling. You can be afraid of the consequences of fear (you might ignobly run away when battle is joined), but the emotion itself is not fearsome. So despite the ability of fear to take objects seemingly at random, it cannot take itself as object—any more than happiness can be feared. Have you ever heard of a case of fear phobia? The statement in question is at best misleading; it must mean something like, “We should be afraid of the consequences of a certain kind of fear, such as violent action”. With respect to fear itself, it is not so labile as to be able to latch onto that.  Can you fear prime numbers or remote galaxies or moral values or electrons? Doubtful—though celery and butterflies evidently can arouse real fear. So fear is not crazily labile, just pretty damn indiscriminate. In understanding and mastering it we need to be aware of its power to mutate and metamorphose and redirect, but we needn’t be concerned to curb it in relation to everything. We must not be paralyzed by fear or dominated by it or bamboozled by it, but we do need to respect its powerfully protean character. It is exceptionally plastic, malleable, and volatile, but not absolutely bonkers. Fear is not a form of insanity, though it comes close sometimes.
Freud thought that sexual desire lies behind almost every aspect of mental life, so that it needs to be understood and regulated; the more plausible view is that fear gets its talons into almost everything, so it needs to be understood and regulated. This applies as much to private life as to international politics. We don’t need to fear fear; but we do urgently need to understand it. It is reported that a few people feel no fear as a result of physical abnormality (the amygdala is supposed to be involved): it is hard for the rest of us to grasp what this must be like (envy would not be inappropriate), but certainly such individuals have a very different mental life from the rest of us. They are not plagued by this wayward, erratic, alarmingly anarchic force; they are not victims of their own cerebral fear centers. The existentialists focused on anxiety (angst) as the prime emotional mover of human life, but fear is surely the more pervasive and active force in our lives, in all its varieties and manifestations. We rightly fear a great many things, but we also unreasonably fear many things too. It is hard not to see our fear responses as a botched evolutionary job—cobbled together, out of control, riddled with design defects. Apparently, different components of it evolved during different evolutionary periods, as ecological demands changed over time; it was not intelligently designed to know its proper scope and limits. Fear is a biological mess, a simmering hodge-podge, and certainly not designed with our happiness in mind (it clearly contraindicates the idea of a divine creator). Not having it at all might not be such a bad idea. Imagine going to the dentist with no fear in your heart! You could still make rational judgments about possible sources of danger, but no more of that nasty oppressive emotion clogging up your brain. We all have to master our fear by effort of will, recognizing that it is not always beneficial; why not make a drug that simply removes it from the human psyche?  Pain, yes, that seems necessary to a safe and successful life; but fear we could definitely live without. Do we really need our eye-watering fear of death? That fear is a serious blight on our life (animals are happily free of it and do quite well in its absence): we don’t need that biting searing debilitating feeling clouding our days! Fear is not something we should simply accept as a fact of life; maybe it is just a temporary aberration in human history. We could certainly do with less of it, or at any rate a more rationally ordered fear economy. Wouldn’t it be nice to live just one day without fear of any kind? 
 When does fear enter human life? It doesn’t seem to exist in the newborn, except perhaps in a very rudimentary form; it awaits the development of reason. It must be a traumatic experience when fear finally makes its appearance: “What is this horribly upsetting feeling I’m having?” The Garden of Eden was clearly a fear-free zone until knowledge and sin introduced fear into human existence. Fear and knowledge are closely intertwined: you can’t fear what you don’t know. When will it be over? Only with death apparently: then fear will be no more.
 What if someone said, “I am not afraid of anything except being afraid”? Wouldn’t we reply: “So you aren’t afraid of the consequences of being afraid either but just of the emotion itself—that makes no sense”. The only way we could be afraid of fear is in virtue of its unpleasant phenomenology—its kinship to pain. But could we be terrified of that unpleasantness? It is like the idea of being in love with love: could you be desperately in love with it? It can’t be just like other love objects. Metaphor is at work in such locutions.
 Then too, there is the question of shame: people tend to be ashamed of their fears and don’t like talking about them. Do we really need the burden of shame in addition to the fear that prompts it? Aren’t we burdened enough already?