The litany against fear is an incantation used by the Bene Gesserit to focus their minds and calm themselves in times of peril. The litany is as follows:
I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.
Lady Jessica teaches it to her son Paul, who uses it when faced with Mohiam’s test of his ability to withstand excruciating pain.