Let's discuss fear.
I was thinking about fear, on how irrational fear is. And absurd.
However, the more I thought about it, the more rational it becomes. At least in the context of human evolution. I hypothesize that fear is a form of safeguard mechanism for humans -- to protect against harm. Or to be scientifically correct: humans who developed a sense of fear survived better throughout generations than humans who didn't. Having fear back then means not doing certain activities that might cause injuries or death, hence better viability.
In that sense, fear is rational.
Fear is still rational nowadays -- in terms of it's usage as a safeguard mechanism. Nevertheless, it can also be irrational when not used to our advantage. For example, fear of rejection, fear of moving on, fear of trying something now, fear of the dark, fear of ghosts, fear of the paranormal. If not controlled, they can be absurd, and dangerous even.
Especially the fear of the paranormal.
Add that fear to the ability of our brain to connect dots and create conclusions. It's where fear would overcome logic and rationality -- and create it's own logic of ghosts and the paranormal.
Safe to say that rationalisation of fear should be done. I should do it.
At the end of the day, fear is rational, but absurd. Context is important.