This has made our race adapt out of fear, making us fear the dark, which was where most of our past predators lurked. Without fear, you would have no hesitation for any action you were about to commit, making the possibilities endless. But fear is what keeps us alive. Fear is what takes over when we look at a blazing fire or down at the ground from the top of a cliff. Many people argue that common sense would take over fear in these situations, but those people are forgetting something. Common sense is created by fear. You are scared heights, so it has been planted in your brain that heights are a bad thing, a common sense created by fear. Fear is your friend, not your foe. Without this evolutionary adaptation, would you even be reading this right now?