For Kierkegaard […], anxiety/dread/angst is unfocused fear. Kierkegaard uses the example of a man standing on the edge of a tall building or cliff. When the man looks over the edge, he experiences a focused fear of falling, but at the same time, the man feels a terrifying impulse to throw himself intentionally off the edge. That experience is anxiety or dread because of our complete freedom to choose to either throw oneself off or to stay put. The mere fact that one has the possibility and freedom to do something, even the most terrifying of possibilities, triggers immense feelings of dread.

Translates literally as “call of the void”. The urge some people get to jump from high places when they encounter them, for example when close to the edge of cliffs.