L’appel du vide is a French philosophical term. The closest English translation to it is “the call of the void”. This is the seemingly unexplained phenomena when people, with no desire to die, are strangely compelled to completely destruct themselves when given the chance. It is most commonly felt when you are :

• on top of a tall building and they feel an urge to leap off.
• on a boat in the middle of the ocean and you feel the urge to jump into the water and sink to the bottom.
• driving along a road that is on the edge of a mountain and you feel the urge to veer the car off the cliff.
• swimming in a deep pool or the ocean and you feel the urge to submerge you whole body in the water and never resurface.
• near a campfire, stove, etc. and you feel the urge to reach out and touch it even though you will burn your hand.
• On the side of a busy road and you want to rush out into it.

None of these urges are really considered suicidal thoughts because even though you have the urge to do something horrible you don’t because you know the consequences are undisputable.

Not all people feel these urges. For example if two tourists go to see the view from the top of the empire state building one of them could be taking pictures and making small talk while the other is clutching the railing to fight the urge to jump. Neither of them wants to die but the second tourist is curious as to what would happen even though they know that they would die if they jump. The basic though process of the second tourist is I will live because I can, but I want to jump because there is a wide open abyss in front of me.

There are many theories that have been developed on why this happens. One is that humans have evolved to be compelled to do the most powerful thing possible in a situation. Even though you don’t have any desire to die, jumping off the cliff is strongest thing you can do in that situation so you are compelled to do it. Some believe that fear of things such as heights doesn’t come from that could happen (i.e. tripping and falling over the edge) but it actually comes from fear that the call of the void will be to strong and that you will want to fall.
Another theory on why this urge occurs is that it is a coping mechanism for anxiety provoking situations. When a person is afraid of things such as falling from a great height or drowning they subconsciously decide that falling or drowning would be less painful than the anxiety their fear provokes. They basically think that checking out of the situation (dying) would be easier than actually dealing with it.