Rational Fear

I've heard of irrational fear. But what makes a fear rational anyways? What makes the fear of pain and danger rational or irrational?

Is the fear of death rational? what about failure? Is it rational to be afraid of the unknown, the uncertain, the unforeseen?

Is there any fear that is truly irrational? Because if it's true to you, isn't it worth fearing? Can't it then be rationalized?

I'm not sure, but one thing I know for certain is that when faced with fear, I'm not sure anyone is truly rational unless they are able to identify the fear as merely a projection of the unknowable future and thus a rejection of the now.

A rational approach to fear.

am not afraid.