The secret to fear? Timing.

The immediacy of panic creates a problem for us persuaders.

Terror turns people instantly obedient. Yell “Duck!” on a crowded sidewalk and watch people crouch. Yell “Fire!” in a theater and… the Supreme Court specifically excluded that from the First Amendment, for the obvious reason that panic can cause a stampede. Similarly, a financial panic can instantly flatten an economy.

In fact, the immediacy of panic creates a problem for useful persuasion. Aristotle defined fear as “a kind of pain or disturbance resulting from the imagination of impending danger, either destructive or harmful.” Impending danger blocks any thinking about the future except for immediate avoidance. When someone yells Hit the deck, you hit the deck. You don’t think about staining your pants and the resulting dry-cleaning bills. Fear also blocks all ambition. You want to protect yourself; you don’t think about improving yourself.

Aristotle also pointed out that fear is a temporary emotion. This makes it a bad long-term motivator. Suppose you have the terrible feeling that you may not fit into your best outfit in time for a cousin’s wedding. That might motivate you temporarily, but fear alone won’t do the trick. The emotion never lasts long enough for an effective diet.

But fear’s ephemeral nature also means it won’t stop you from learning a daunting skill. Remember when you first learned to drive, and how scary it seemed to be behind the wheel of a two-ton death machine? And how driving on the interstate for the first time made you taste your own heart? You probably got used to it after a while. If fear comes from “the imagination of impending danger,” then your imagination can turn it off. The danger may be real—have you seen how people drive?—but the fear itself is a mere figment.

While you probably know ways to calm yourself—breathing, relaxing your shoulders, taking a bath—when it comes to talking yourself into accomplishing something or going to the gym, dealing with fear is more a matter of timing. Fear rarely lasts.

An exception to this rule is when you suffer from a neurosis; in this case, therapy should come before rhetoric. Or maybe you have a fearful soul—an overactive amygdala, or a doomsaying imagination.

Some otherwise well-adjusted people frame fear as prudence, a quality of practical wisdom, the Craft part of an admirable ethos. These cautious souls show up at the airport four hours early out of fear of missing the flight and waiting a couple hours for the next one. To a different person, this seems utterly irrational. But to them, if their identity coddles their fear, they take a sort of pride in that emotion. Whole industries—gun manufacturing, home security—spend vast amounts to make us identify with fear. An ancient philosopher would describe these media as poison for the soul.

Aristotle’s answer to this habitual sort of fear is to assess each danger. How immediate is it? How dangerous is it truly?

When our children were little, Dorothy Sr. would get nervous seeing them on the playground jungle gym. “Be careful, you’ll fall!” she’d yell. She meant, “If you’re careful you won’t fall.” Her version emphasized fear, which might enhance the child’s safety but result in a fearful soul. The second, more positive version would have emphasized skill and agency. When I would helpfully point out this difference, though, Dorothy would tell me to shush. She was the mother, and I feared her motherly wrath.

If a piano falls from a window above you, let your fear take over. If it’s a crime committed in some other state, assess the actual danger to you. Let your rational side bend your fearful soul.