"The primary thing when you take a sword in your hands is your intention to cut the enemy, whatever the means. Whenever you parry, hit, spring, strike or touch the enemy's cutting sword, you must cut the enemy in the same movement. It is essential to attain this. If you think only of hitting, springing, striking or touching the enemy, you will not be able actually to cut him."
--Miyamoto Musashi, from The Book of Five Rings
When you're actively afraid, you know it. You can feel the fear pressing against you. Maybe you work through it and conquer it this time, or maybe you don't. But if you succeed, you know you worked through the fear. And you know if you fail, the fear beat you.
This is the type of fear you feel when you're about to do public speaking, make a cold call, ask for a raise at work, or do a difficult ski run.
And maybe sometimes you back down from whatever it is you were afraid of. It happens, and it's not the end of the world when it does. Fear winds up beating most people at least sometimes, in some domain.
Passive fear, on the other hand, is far more insidious. It's what Pressfield called "The Resistance" in The War of Art. It's a form of fear, but not one that shows itself. It's sneaky. You find the need to do some lower importance activity instead of doing your work.
Excuses abound, the important things don't get done.